Implement video frame acknowledgements in the chromoting protocol.

remoting/protocol/client_video_dispatcher_unittest.cc

+// Copyright 2015 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 "remoting/protocol/client_video_dispatcher.h"
+
+#include "base/bind.h"
+#include "base/memory/scoped_vector.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "remoting/base/constants.h"
+#include "remoting/proto/video.pb.h"
+#include "remoting/protocol/fake_session.h"
+#include "remoting/protocol/fake_stream_socket.h"
+#include "remoting/protocol/message_serialization.h"
+#include "remoting/protocol/video_stub.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace remoting {
+namespace protocol {
+
+class ClientVideoDispatcherTest : public testing::Test,
+                                  public VideoStub,
+                                  public ChannelDispatcherBase::EventHandler {
+ public:
+  ClientVideoDispatcherTest()
+      : initialized_(false),
+        dispatcher_(this),
+        parser_(base::Bind(&ClientVideoDispatcherTest::OnVideoAck,
+                           base::Unretained(this)),
+                &reader_) {
+  }
+
+  void InitializeWithProtocolVersion(int version) {
+    dispatcher_.Init(&session_,
+                     ChannelConfig(ChannelConfig::TRANSPORT_MUX_STREAM, version,
+                                   ChannelConfig::CODEC_UNDEFINED),
+                     this);
+    base::RunLoop().RunUntilIdle();
+    DCHECK(initialized_);
+    host_socket_.PairWith(
+        session_.fake_channel_factory().GetFakeChannel(kVideoChannelName));
+    reader_.StartReading(&host_socket_);
+    writer_.Init(&host_socket_, BufferedSocketWriter::WriteFailedCallback());
+  }
+
+  // VideoStub interface.
+  void ProcessVideoPacket(scoped_ptr<VideoPacket> video_packet,
+                          const ProgressCallback& progress_callback) {
+    video_packets_.push_back(video_packet.release());
+    packet_progress_callbacks_.push_back(progress_callback);
+  }
+
+  // ChannelDispatcherBase::EventHandler interface.
+  void OnChannelInitialized(ChannelDispatcherBase* channel_dispatcher) {
+    initialized_ = true;
+  }
+  void OnChannelError(ChannelDispatcherBase* channel_dispatcher,
+                      ErrorCode error) {
+    // Don't expect channel creation to fail.
+    FAIL();
+  }
+
+ protected:
+  void OnVideoAck(scoped_ptr<VideoAck> ack, const base::Closure& done) {
+    ack_messages_.push_back(ack.release());
+    done.Run();
+  }
+
+  base::MessageLoop message_loop_;
+
+  // Set to true in OnChannelInitialized().
+  bool initialized_;
+
+  // Client side.
+  ClientVideoDispatcher dispatcher_;
+  FakeSession session_;
+
+  // Host side.
+  FakeStreamSocket host_socket_;
+  MessageReader reader_;
+  ProtobufMessageParser<VideoAck> parser_;
+  BufferedSocketWriter writer_;
+
+  ScopedVector<VideoPacket> video_packets_;
+  std::vector<ProgressCallback> packet_progress_callbacks_;
+
+  ScopedVector<VideoAck> ack_messages_;
+};
+
+// Verify that the client can receive video packets and acks are not sent for
+// older versions of the protocol.
+TEST_F(ClientVideoDispatcherTest, WithoutAcks) {
+  int kTestFrameId = 3;
+
+  InitializeWithProtocolVersion(kVideoStreamVersionNoAck);
+
+  VideoPacket packet;
+  packet.set_data(std::string());
+  packet.set_frame_id(kTestFrameId);
+
+  // Send a VideoPacket and verify that the client receives it.
+  writer_.Write(SerializeAndFrameMessage(packet), base::Closure());
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1U, video_packets_.size());
+
+  packet_progress_callbacks_.front().Run(VideoStub::PacketProgress::DONE);
+  base::RunLoop().RunUntilIdle();
+
+  // Ack should never be sent for this version of the protocol.
+  EXPECT_TRUE(ack_messages_.empty());
+}
+
+// Verifies that the dispatcher sends Ack message with correct rendering delay.
+TEST_F(ClientVideoDispatcherTest, WithAcks) {
+  int kTestFrameId = 3;
+
+  InitializeWithProtocolVersion(kVideoStreamVersion);
+
+  VideoPacket packet;
+  packet.set_data(std::string());
+  packet.set_frame_id(kTestFrameId);
+
+  // Send a VideoPacket and verify that the client receives it.
+  base::TimeTicks write_started_time = base::TimeTicks::Now();
+  writer_.Write(SerializeAndFrameMessage(packet), base::Closure());
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1U, video_packets_.size());
+
+  // Ack should only be sent after the packet is processed.
+  EXPECT_TRUE(ack_messages_.empty());
+
+  // Simulate frame render delay.
+  base::TimeTicks render_started_time = base::TimeTicks::Now();
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(1));
+  base::TimeDelta render_delay_min =
+      base::TimeTicks::Now() - render_started_time;
+
+  //Fake completion of video packet decoding, to trigger the Ack.
+  packet_progress_callbacks_.front().Run(VideoStub::PacketProgress::DONE);
+  base::TimeDelta render_delay_max =
+      base::TimeTicks::Now() - write_started_time;
+
+  base::RunLoop().RunUntilIdle();
+  ASSERT_EQ(1U, ack_messages_.size());
+  EXPECT_EQ(kTestFrameId, ack_messages_[0]->frame_id());
+
+  // Verify that rendering latency is reported correctly.
+  base::TimeDelta render_delay =
+      base::TimeDelta::FromMicroseconds(ack_messages_[0]->rendering_delay_us());
+  EXPECT_TRUE(render_delay >= render_delay_min);
+  EXPECT_TRUE(render_delay <= render_delay_max);
+}
+
+// Verifies that the dispatcher reports correct read delay in the messages it
+// receives.
+TEST_F(ClientVideoDispatcherTest, ReadDelay) {
+  int kTestFrameId = 3;
+
+  InitializeWithProtocolVersion(kVideoStreamVersion);
+
+  VideoPacket packet;
+  packet.set_data(std::string());
+  packet.set_frame_id(kTestFrameId);
+
+  // Generate buffers for two video frames.
+  scoped_refptr<net::IOBufferWithSize> packet_buffer_1 =
+      SerializeAndFrameMessage(packet);
+  packet.set_frame_id(kTestFrameId + 1);
+  scoped_refptr<net::IOBufferWithSize> packet_buffer_2 =
+      SerializeAndFrameMessage(packet);
+  packet.set_frame_id(kTestFrameId + 2);
+  scoped_refptr<net::IOBufferWithSize> packet_buffer_3 =
+      SerializeAndFrameMessage(packet);
+
+  base::TimeTicks send_started_time = base::TimeTicks::Now();
+
+  // First send all data for the first frame and the first byte for the second
+  // frame in a single network packet.
+  scoped_refptr<net::IOBufferWithSize> buffer =
+      new net::IOBufferWithSize(packet_buffer_1->size() + 1);
+  memcpy(buffer->data(), packet_buffer_1->data(), packet_buffer_1->size());
+  memcpy(buffer->data() + packet_buffer_1->size(), packet_buffer_2->data(), 1);
+  writer_.Write(buffer, base::Closure());
+  base::RunLoop().RunUntilIdle();
+
+  // Verify that the packet was received.
+  EXPECT_EQ(1U, video_packets_.size());
+  video_packets_.clear();
+  packet_progress_callbacks_.front().Run(VideoStub::PacketProgress::DONE);
+  packet_progress_callbacks_.clear();
+  base::RunLoop().RunUntilIdle();
+
+  // Verify that the Ack message for the first video frame has time_to_receive
+  // field set to 0, because the whole frame was received in one message.
+  ASSERT_EQ(1U, ack_messages_.size());
+  EXPECT_EQ(kTestFrameId, ack_messages_[0]->frame_id());
+  EXPECT_EQ(0, ack_messages_[0]->time_to_receive_us());
+  ack_messages_.clear();
+
+  // Simulate networking latency while receiving the second frame.
+  base::TimeTicks network_delay_started_time = base::TimeTicks::Now();
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(1));
+  base::TimeDelta time_to_receive_min =
+      base::TimeTicks::Now() - network_delay_started_time;
+
+  // Send the remainder of the second frame.
+  buffer = new net::IOBufferWithSize(packet_buffer_2->size() - 1 +
+                                     packet_buffer_3->size());
+  memcpy(buffer->data(), packet_buffer_2->data() + 1,
+         packet_buffer_2->size() - 1);
+  memcpy(buffer->data() + packet_buffer_2->size() - 1, packet_buffer_3->data(),
+         packet_buffer_3->size());
+  writer_.Write(buffer, base::Closure());
+  base::RunLoop().RunUntilIdle();
+
+  base::TimeDelta time_to_receive_max =
+      base::TimeTicks::Now() - send_started_time;
+
+  // Verify that the last 2 packets were received.
+  EXPECT_EQ(2U, video_packets_.size());
+  packet_progress_callbacks_[0].Run(VideoStub::PacketProgress::DONE);
+  packet_progress_callbacks_[1].Run(VideoStub::PacketProgress::DONE);
+  base::RunLoop().RunUntilIdle();
+
+  // Verify that we've received 2 Ack for the last 2 frames.
+  ASSERT_EQ(2U, ack_messages_.size());
+  EXPECT_EQ(kTestFrameId + 1, ack_messages_[0]->frame_id());
+
+  // Verify that the dispatcher set correct time_to_receive value.
+  base::TimeDelta time_to_receive =
+      base::TimeDelta::FromMicroseconds(ack_messages_[0]->time_to_receive_us());
+  EXPECT_TRUE(time_to_receive >= time_to_receive_min);
+  EXPECT_TRUE(time_to_receive <= time_to_receive_max);
+
+  EXPECT_EQ(kTestFrameId + 2, ack_messages_[1]->frame_id());
+  EXPECT_EQ(0, ack_messages_[1]->time_to_receive_us());
+}
+
+}  // namespace protocol
+}  // namespace remoting