Adding basic implementation of AudioNetworkAdaptor.

webrtc/modules/audio_coding/audio_network_adaptor/controller_manager.h

+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_CONTROLLER_MANAGER_H_
+#define WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_CONTROLLER_MANAGER_H_
+
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_coding/audio_network_adaptor/controller.h"
+
+namespace webrtc {
+
+class ControllerManager {
+ public:
+  virtual ~ControllerManager() = default;
+
+  // Sort controllers based on their significance.
+  virtual std::vector<Controller*> GetSortedControllers(
+      const Controller::NetworkMetrics& metrics) = 0;
+
+  virtual std::vector<Controller*> GetControllers() const = 0;
+};

[kwiberg-webrtc, 2016/09/13 11:11:42]

Clean split between interface and implementation. Good!

+
+class ControllerManagerImpl final : public ControllerManager {
+ public:
+  struct Config {
+    Config();
+    ~Config();
+  };

[kwiberg-webrtc, 2016/09/13 11:11:42]

This one doesn't seem to be doing anything important...

+
+  explicit ControllerManagerImpl(const Config& config);

[kwiberg-webrtc, 2016/09/13 11:11:42]

This constructor seems useless. I assume later CLs will change that?

+
+  // Dependency injection for testing.
+  ControllerManagerImpl(const Config& config,
+                        std::vector<std::unique_ptr<Controller>> controllers);

[kwiberg-webrtc, 2016/09/13 11:11:42]

Consider whether the same arguments as for AudioNetworkAdaptorImpl would argue
for not having a separate dependency injection constructor here too. The current
state of the code definitely says there doesn't need to be two constructors, but
you have more changes lined up that aren't visible here.

[minyue-webrtc, 2016/09/13 11:48:50]

Yes, ControllerManagerImpl(const Config& config) is supposed to create all
controllers according to Config. This is not at all seen in this CL. Leaving
some place-holding code here is to illustrate what it will look like in the
future. 

[kwiberg-webrtc, 2016/09/13 12:34:57]

OK. I expect I'll have further comments on this topic when I see the actual
code, but that can wait for later.

+
+  ~ControllerManagerImpl() override;
+
+  // Sort controllers based on their significance.
+  std::vector<Controller*> GetSortedControllers(
+      const Controller::NetworkMetrics& metrics) override;
+
+  std::vector<Controller*> GetControllers() const override;
+
+ private:
+  const Config config_;
+
+  std::vector<std::unique_ptr<Controller>> controllers_;
+
+  std::vector<Controller*> default_sorted_controllers_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(ControllerManagerImpl);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_CONTROLLER_MANAGER_H_