| /* |
| * Copyright (c) 2012 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 <algorithm> |
| |
| #include "testing/gtest/include/gtest/gtest.h" |
| #include "webrtc/base/rate_statistics.h" |
| |
| namespace { |
| |
| using webrtc::RateStatistics; |
| |
| const int64_t kWindowMs = 500; |
| |
| class RateStatisticsTest : public ::testing::Test { |
| protected: |
| RateStatisticsTest() : stats_(kWindowMs, 8000) {} |
| RateStatistics stats_; |
| }; |
| |
| TEST_F(RateStatisticsTest, TestStrictMode) { |
| int64_t now_ms = 0; |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| const uint32_t kPacketSize = 1500u; |
| const uint32_t kExpectedRateBps = kPacketSize * 1000 * 8; |
| |
| // Single data point is not enough for valid estimate. |
| stats_.Update(kPacketSize, now_ms++); |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| // Expecting 1200 kbps since the window is initially kept small and grows as |
| // we have more data. |
| stats_.Update(kPacketSize, now_ms); |
| EXPECT_EQ(kExpectedRateBps, *stats_.Rate(now_ms)); |
| |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| const int kInterval = 10; |
| for (int i = 0; i < 100000; ++i) { |
| if (i % kInterval == 0) |
| stats_.Update(kPacketSize, now_ms); |
| |
| // Approximately 1200 kbps expected. Not exact since when packets |
| // are removed we will jump 10 ms to the next packet. |
| if (i > kInterval) { |
| rtc::Optional<uint32_t> rate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(rate)); |
| uint32_t samples = i / kInterval + 1; |
| uint64_t total_bits = samples * kPacketSize * 8; |
| uint32_t rate_bps = static_cast<uint32_t>((1000 * total_bits) / (i + 1)); |
| EXPECT_NEAR(rate_bps, *rate, 22000u); |
| } |
| now_ms += 1; |
| } |
| now_ms += kWindowMs; |
| // The window is 2 seconds. If nothing has been received for that time |
| // the estimate should be 0. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| } |
| |
| TEST_F(RateStatisticsTest, IncreasingThenDecreasingBitrate) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| stats_.Update(1000, ++now_ms); |
| const uint32_t kExpectedBitrate = 8000000; |
| // 1000 bytes per millisecond until plateau is reached. |
| int prev_error = kExpectedBitrate; |
| rtc::Optional<uint32_t> bitrate; |
| while (++now_ms < 10000) { |
| stats_.Update(1000, now_ms); |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| int error = kExpectedBitrate - *bitrate; |
| error = std::abs(error); |
| // Expect the estimation error to decrease as the window is extended. |
| EXPECT_LE(error, prev_error + 1); |
| prev_error = error; |
| } |
| // Window filled, expect to be close to 8000000. |
| EXPECT_EQ(kExpectedBitrate, *bitrate); |
| |
| // 1000 bytes per millisecond until 10-second mark, 8000 kbps expected. |
| while (++now_ms < 10000) { |
| stats_.Update(1000, now_ms); |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_EQ(kExpectedBitrate, *bitrate); |
| } |
| |
| // Zero bytes per millisecond until 0 is reached. |
| while (++now_ms < 20000) { |
| stats_.Update(0, now_ms); |
| rtc::Optional<uint32_t> new_bitrate = stats_.Rate(now_ms); |
| if (static_cast<bool>(new_bitrate) && *new_bitrate != *bitrate) { |
| // New bitrate must be lower than previous one. |
| EXPECT_LT(*new_bitrate, *bitrate); |
| } else { |
| // 0 kbps expected. |
| EXPECT_EQ(0u, *new_bitrate); |
| break; |
| } |
| bitrate = new_bitrate; |
| } |
| |
| // Zero bytes per millisecond until 20-second mark, 0 kbps expected. |
| while (++now_ms < 20000) { |
| stats_.Update(0, now_ms); |
| EXPECT_EQ(0u, *stats_.Rate(now_ms)); |
| } |
| } |
| |
| TEST_F(RateStatisticsTest, ResetAfterSilence) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| const uint32_t kExpectedBitrate = 8000000; |
| // 1000 bytes per millisecond until the window has been filled. |
| int prev_error = kExpectedBitrate; |
| rtc::Optional<uint32_t> bitrate; |
| while (++now_ms < 10000) { |
| stats_.Update(1000, now_ms); |
| bitrate = stats_.Rate(now_ms); |
| if (bitrate) { |
| int error = kExpectedBitrate - *bitrate; |
| error = std::abs(error); |
| // Expect the estimation error to decrease as the window is extended. |
| EXPECT_LE(error, prev_error + 1); |
| prev_error = error; |
| } |
| } |
| // Window filled, expect to be close to 8000000. |
| EXPECT_EQ(kExpectedBitrate, *bitrate); |
| |
| now_ms += kWindowMs + 1; |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| stats_.Update(1000, now_ms); |
| ++now_ms; |
| stats_.Update(1000, now_ms); |
| // We expect two samples of 1000 bytes, and that the bitrate is measured over |
| // 500 ms, i.e. 2 * 8 * 1000 / 0.500 = 32000. |
| EXPECT_EQ(32000u, *stats_.Rate(now_ms)); |
| |
| // Reset, add the same samples again. |
| stats_.Reset(); |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| stats_.Update(1000, now_ms); |
| ++now_ms; |
| stats_.Update(1000, now_ms); |
| // We expect two samples of 1000 bytes, and that the bitrate is measured over |
| // 2 ms (window size has been reset) i.e. 2 * 8 * 1000 / 0.002 = 8000000. |
| EXPECT_EQ(kExpectedBitrate, *stats_.Rate(now_ms)); |
| } |
| |
| TEST_F(RateStatisticsTest, HandlesChangingWindowSize) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| |
| // Sanity test window size. |
| EXPECT_TRUE(stats_.SetWindowSize(kWindowMs, now_ms)); |
| EXPECT_FALSE(stats_.SetWindowSize(kWindowMs + 1, now_ms)); |
| EXPECT_FALSE(stats_.SetWindowSize(0, now_ms)); |
| EXPECT_TRUE(stats_.SetWindowSize(1, now_ms)); |
| EXPECT_TRUE(stats_.SetWindowSize(kWindowMs, now_ms)); |
| |
| // Fill the buffer at a rate of 1 byte / millisecond (8 kbps). |
| const int kBatchSize = 10; |
| for (int i = 0; i <= kWindowMs; i += kBatchSize) |
| stats_.Update(kBatchSize, now_ms += kBatchSize); |
| EXPECT_EQ(static_cast<uint32_t>(8000), *stats_.Rate(now_ms)); |
| |
| // Halve the window size, rate should stay the same. |
| EXPECT_TRUE(stats_.SetWindowSize(kWindowMs / 2, now_ms)); |
| EXPECT_EQ(static_cast<uint32_t>(8000), *stats_.Rate(now_ms)); |
| |
| // Double the window size again, rate should stay the same. (As the window |
| // won't actually expand until new bit and bobs fall into it. |
| EXPECT_TRUE(stats_.SetWindowSize(kWindowMs, now_ms)); |
| EXPECT_EQ(static_cast<uint32_t>(8000), *stats_.Rate(now_ms)); |
| |
| // Fill the now empty half with bits it twice the rate. |
| for (int i = 0; i < kWindowMs / 2; i += kBatchSize) |
| stats_.Update(kBatchSize * 2, now_ms += kBatchSize); |
| |
| // Rate should have increase be 50%. |
| EXPECT_EQ(static_cast<uint32_t>((8000 * 3) / 2), *stats_.Rate(now_ms)); |
| } |
| |
| TEST_F(RateStatisticsTest, RespectsWindowSizeEdges) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| // One byte per ms, using one big sample. |
| stats_.Update(kWindowMs, now_ms); |
| now_ms += kWindowMs - 2; |
| // Shouldn't work! (Only one sample, not full window size.) |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| // Window size should be full, and the single data point should be accepted. |
| ++now_ms; |
| rtc::Optional<uint32_t> bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(1000 * 8u, *bitrate); |
| |
| // Add another, now we have twice the bitrate. |
| stats_.Update(kWindowMs, now_ms); |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(2 * 1000 * 8u, *bitrate); |
| |
| // Now that first sample should drop out... |
| now_ms += 1; |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(1000 * 8u, *bitrate); |
| } |
| |
| TEST_F(RateStatisticsTest, HandlesZeroCounts) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| stats_.Update(kWindowMs, now_ms); |
| now_ms += kWindowMs - 1; |
| stats_.Update(0, now_ms); |
| rtc::Optional<uint32_t> bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(1000 * 8u, *bitrate); |
| |
| // Move window along so first data point falls out. |
| ++now_ms; |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(0u, *bitrate); |
| |
| // Move window so last data point falls out. |
| now_ms += kWindowMs; |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| } |
| |
| TEST_F(RateStatisticsTest, HandlesQuietPeriods) { |
| int64_t now_ms = 0; |
| stats_.Reset(); |
| // Expecting 0 after init. |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| stats_.Update(0, now_ms); |
| now_ms += kWindowMs - 1; |
| rtc::Optional<uint32_t> bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(0u, *bitrate); |
| |
| // Move window along so first data point falls out. |
| ++now_ms; |
| EXPECT_FALSE(static_cast<bool>(stats_.Rate(now_ms))); |
| |
| // Move window a long way out. |
| now_ms += 2 * kWindowMs; |
| stats_.Update(0, now_ms); |
| bitrate = stats_.Rate(now_ms); |
| EXPECT_TRUE(static_cast<bool>(bitrate)); |
| EXPECT_EQ(0u, *bitrate); |
| } |
| } // namespace |