Fire canplaythrough event at the proper time for audio/video

media/base/download_rate_monitor_unittest.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/base/download_rate_monitor.h"
+
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ::testing::Mock;
+
+namespace media {
+
+class DownloadRateMonitorTest : public ::testing::Test {
+ public:
+  DownloadRateMonitorTest() {
+    monitor_.set_total_bytes(kMediaSizeInBytes);
+  }
+
+  virtual ~DownloadRateMonitorTest() { }
+
+  MOCK_METHOD0(CanPlayThrough, void());
+
+ protected:
+  static const int kMediaSizeInBytes = 20 * 1024 * 1024;
+
+  // Simulates downloading of the media file. Packets are timed evenly in
+  // |ms_between_packets| intervals, starting at |starting_time|, which is
+  // number of seconds since unix epoch (Jan 1, 1970).
+  // Returns the number of bytes buffered in the media file after the
+  // network activity.
+  int SimulateNetwork(double starting_time,
+                      int starting_bytes,
+                      int bytes_per_packet,
+                      int ms_between_packets,
+                      int number_of_packets) {
+    int bytes_buffered = starting_bytes;
+    base::Time packet_time = base::Time::FromDoubleT(starting_time);
+
+    monitor_.SetNetworkActivity(true);
+    // Loop executes (number_of_packets + 1) times because a packet needs a
+    // starting and end point.
+    for (int i = 0; i < number_of_packets + 1; ++i) {
+      monitor_.SetBufferedBytes(bytes_buffered, packet_time);
+      packet_time += base::TimeDelta::FromMilliseconds(ms_between_packets);
+      bytes_buffered += bytes_per_packet;
+    }
+    monitor_.SetNetworkActivity(false);
+    return bytes_buffered;
+  }
+
+  DownloadRateMonitor monitor_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DownloadRateMonitorTest);
+};
+
+TEST_F(DownloadRateMonitorTest, DownloadRateGreaterThanBitrate) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+
+  // Simulate downloading at double the media's bitrate.
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  EXPECT_CALL(*this, CanPlayThrough());
+  SimulateNetwork(1, 0, 2 * media_bitrate / 8, 1000, 10);
+}
+
+// If the user pauses and the pipeline stops downloading data, make sure the
+// DownloadRateMonitor understands that the download is not stalling.
+TEST_F(DownloadRateMonitorTest, DownloadRateGreaterThanBitrate_Pause) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+  static const int download_byte_rate = 1.1 * media_bitrate / 8;
+
+  // Start downloading faster than the media's bitrate.
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  EXPECT_CALL(*this, CanPlayThrough());
+  int buffered = SimulateNetwork(1, 0, download_byte_rate, 1000, 2);
+
+  // Then "pause" for 3 minutes and continue downloading at same rate.
+  SimulateNetwork(60 * 3, buffered, download_byte_rate, 1000, 4);
+}
+
+TEST_F(DownloadRateMonitorTest, DownloadRateGreaterThanBitrate_SeekForward) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+  static const int download_byte_rate = 1.1 * media_bitrate / 8;
+
+  // Start downloading faster than the media's bitrate.
+  EXPECT_CALL(*this, CanPlayThrough());
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  SimulateNetwork(1, 0, download_byte_rate, 1000, 2);
+
+  // Then seek forward mid-file and continue downloading at same rate.
+  SimulateNetwork(4, kMediaSizeInBytes / 2, download_byte_rate, 1000, 4);
+}
+
+TEST_F(DownloadRateMonitorTest, DownloadRateGreaterThanBitrate_SeekBackward) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+  static const int download_byte_rate = 1.1 * media_bitrate / 8;
+
+  // Start downloading faster than the media's bitrate, in middle of file.
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  SimulateNetwork(1, kMediaSizeInBytes / 2, download_byte_rate, 1000, 2);
+
+  // Then seek back to beginning and continue downloading at same rate.
+  EXPECT_CALL(*this, CanPlayThrough());
+  SimulateNetwork(4, 0, download_byte_rate, 1000, 4);
+}
+
+TEST_F(DownloadRateMonitorTest, DownloadRateLessThanBitrate) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+
+  // Simulate downloading at half the media's bitrate.
+  EXPECT_CALL(*this, CanPlayThrough())
+      .Times(0);
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  SimulateNetwork(1, 0, media_bitrate / 8 / 2, 1000, 10);
+}
+
+TEST_F(DownloadRateMonitorTest, MediaIsLoaded) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+
+  monitor_.set_loaded(true);
+
+  // Simulate no data downloaded (source is already loaded).
+  EXPECT_CALL(*this, CanPlayThrough());
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  SimulateNetwork(1, 0, 0, 1000, 10);
+}
+
+TEST_F(DownloadRateMonitorTest, VeryFastDownloadRate) {
+  static const int media_bitrate = 1024 * 1024 * 8;
+
+  // Simulate downloading half the video very quickly in one chunk.
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  EXPECT_CALL(*this, CanPlayThrough());
+  SimulateNetwork(1, 0, kMediaSizeInBytes / 2, 10, 1);
+}
+
+TEST_F(DownloadRateMonitorTest, DownloadEntireVideo) {
+  static const int seconds_of_data = 20;
+  static const int media_bitrate = kMediaSizeInBytes * 8 / seconds_of_data;
+
+  // Simulate downloading entire video at half the bitrate of the video.
+  monitor_.Start(base::Bind(&DownloadRateMonitorTest::CanPlayThrough,
+                            base::Unretained(this)), media_bitrate);
+  EXPECT_CALL(*this, CanPlayThrough());
+  SimulateNetwork(1, 0, media_bitrate / 8 / 2, 1000, seconds_of_data * 2);
+}
+
+}  // namespace media