Fix AudioPump to pause the stream when the network is congested.

remoting/host/audio_pump_unittest.cc

Index: remoting/host/audio_pump_unittest.cc
diff --git a/remoting/host/audio_pump_unittest.cc b/remoting/host/audio_pump_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8d0ac5d57acf928feadb5e7fea6cab1b603af38a
--- /dev/null
+++ b/remoting/host/audio_pump_unittest.cc
@@ -0,0 +1,140 @@
+// 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/host/audio_pump.h"
+
+#include "base/memory/scoped_vector.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "remoting/codec/audio_encoder.h"
+#include "remoting/host/audio_capturer.h"
+#include "remoting/proto/audio.pb.h"
+#include "remoting/protocol/audio_stub.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace remoting {
+
+namespace {
+
+// Creates a dummy packet with 1k data
+scoped_ptr<AudioPacket> MakeAudioPacket() {
+  scoped_ptr<AudioPacket> packet(new AudioPacket);
+  packet->add_data()->resize(1000);
+  return packet.Pass();
+}
+
+}  // namespace
+
+class FakeAudioCapturer : public AudioCapturer {
+ public:
+  FakeAudioCapturer() {}
+  ~FakeAudioCapturer() override {}
+
+  bool Start(const PacketCapturedCallback& callback) override {
+    callback_ = callback;
+    return true;
+  }
+
+  const PacketCapturedCallback& callback() { return callback_; }
+
+ private:
+  PacketCapturedCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeAudioCapturer);
+};
+
+class FakeAudioEncoder : public AudioEncoder {
+ public:
+  FakeAudioEncoder() {}
+  ~FakeAudioEncoder() override {}
+
+  scoped_ptr<AudioPacket> Encode(scoped_ptr<AudioPacket> packet) override {
+    return packet.Pass();
+  }
+  int GetBitrate() override {
+    return 160000;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(FakeAudioEncoder);
+};
+
+class AudioPumpTest : public testing::Test, public protocol::AudioStub {
+ public:
+  AudioPumpTest() {}
+
+  void SetUp() override;
+  void TearDown() override;
+
+  // protocol::AudioStub interface.
+  void ProcessAudioPacket(scoped_ptr<AudioPacket> audio_packet,
+                          const base::Closure& done) override;
+
+ protected:
+  base::MessageLoop message_loop_;
+
+  // |capturer_| and |encoder_| are owned by the |pump_|.
+  FakeAudioCapturer* capturer_;
+  FakeAudioEncoder* encoder_;
+
+  scoped_ptr<AudioPump> pump_;
+
+  ScopedVector<AudioPacket> sent_packets_;
+  std::vector<base::Closure> done_closures_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AudioPumpTest);
+};
+
+void AudioPumpTest::SetUp() {
+  capturer_ = new FakeAudioCapturer();
+  encoder_ = new FakeAudioEncoder();
+  pump_.reset(new AudioPump(message_loop_.task_runner(),
+                            make_scoped_ptr(capturer_),
+                            make_scoped_ptr(encoder_), this));
+}
+
+void AudioPumpTest::TearDown() {
+  pump_.reset();
+
+  // Let the message loop run to finish destroying the capturer.
+  base::RunLoop().RunUntilIdle();
+}
+
+void AudioPumpTest::ProcessAudioPacket(
+    scoped_ptr<AudioPacket> audio_packet,
+    const base::Closure& done) {
+  sent_packets_.push_back(audio_packet.Pass());
+  done_closures_.push_back(done);
+}
+
+// Verify that the pump pauses pumping when the network is congested.
+TEST_F(AudioPumpTest, BufferSizeLimit) {
+  // Run message loop to let the pump start the capturer.
+  base::RunLoop().RunUntilIdle();
+  ASSERT_FALSE(capturer_->callback().is_null());
+
+  // Try sending 100 packets, 1k each. The pump should stop pumping and start
+  // dropping the data at some point.
+  for (size_t i = 0; i < 100; ++i) {
+    capturer_->callback().Run(MakeAudioPacket());
+    base::RunLoop().RunUntilIdle();
+  }
+
+  size_t num_sent_packets = sent_packets_.size();
+  EXPECT_LT(num_sent_packets, 100U);
+  EXPECT_GT(num_sent_packets, 0U);
+
+  // Call done closure for the first packet. This should allow one more packet
+  // to be sent below.
+  done_closures_.front().Run();
+  base::RunLoop().RunUntilIdle();
+
+  // Verify that the pump continues to send captured audio.
+  capturer_->callback().Run(MakeAudioPacket());
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(num_sent_packets + 1, sent_packets_.size());
+}
+
+}  // namespace remoting