[Media Router] Add CastMediaSinkService

chrome/browser/media/router/discovery/mdns/cast_media_sink_service.h

+// Copyright 2017 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.
+
+#ifndef CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_CAST_MEDIA_SINK_SERVICE_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_CAST_MEDIA_SINK_SERVICE_H_
+
+#include <memory>
+#include <set>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/threading/thread_checker.h"
+#include "chrome/browser/media/router/discovery/mdns/dns_sd_delegate.h"
+#include "chrome/browser/media/router/discovery/mdns/dns_sd_registry.h"
+#include "chrome/browser/media/router/discovery/media_sink_service_base.h"
+#include "components/cast_channel/cast_channel_enum.h"
+#include "components/cast_channel/cast_socket.h"
+#include "net/base/ip_endpoint.h"
+
+namespace cast_channel {
+class CastSocketService;
+}  // namespace cast_channel
+
+namespace content {
+class BrowserContext;
+}  // namespace content
+
+namespace media_router {
+
+// A service which can be used to start background discovery and resolution of
+// Cast devices.
+// Public APIs should be invoked on the UI thread.
+class CastMediaSinkService
+    : public MediaSinkServiceBase,
+      public DnsSdRegistry::DnsSdObserver,
+      public base::RefCountedThreadSafe<CastMediaSinkService> {
+ public:
+  CastMediaSinkService(const OnSinksDiscoveredCallback& callback,
+                       content::BrowserContext* browser_context);
+
+  // Used by unit tests.
+  CastMediaSinkService(const OnSinksDiscoveredCallback& callback,
+                       cast_channel::CastSocketService* cast_socket_service);
+
+  // MediaSinkService implementation
+  void Start() override;
+  void Stop() override;
+
+ protected:
+  // Used to mock out the DnsSdRegistry for testing.
+  void SetDnsSdRegistryForTest(DnsSdRegistry* registry);

[imcheng, 2017/06/29 23:15:44]

Can you set DnsSdRegistry in the test constructor?

[zhaobin, 2017/07/05 18:01:37]

We are going to keep this function and remove |test_dns_sd_registry_| instead.

+
+  ~CastMediaSinkService() override;
+
+ private:
+  // Receives incoming messages and errors and provides additional API context.
+  class CastSocketObserver : public cast_channel::CastSocket::Observer {
+   public:
+    CastSocketObserver();
+    ~CastSocketObserver() override;
+
+    // CastSocket::Observer implementation.
+    void OnError(const cast_channel::CastSocket& socket,
+                 cast_channel::ChannelError error_state) override;
+    void OnMessage(const cast_channel::CastSocket& socket,
+                   const cast_channel::CastMessage& message) override;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(CastSocketObserver);
+  };
+
+  friend class base::RefCountedThreadSafe<CastMediaSinkService>;
+  friend class CastMediaSinkServiceTest;
+
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest, TestReStartAfterStop);
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest,
+                           TestOnChannelOpenedOnIOThread);
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest,
+                           TestMultipleOnChannelOpenedOnIOThread);
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest, TestOnDnsSdEvent);
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest, TestMultipleOnDnsSdEvent);
+  FRIEND_TEST_ALL_PREFIXES(CastMediaSinkServiceTest, TestTimer);
+
+  // DnsSdRegistry::DnsSdObserver implementation
+  void OnDnsSdEvent(const std::string& service_type,
+                    const DnsSdRegistry::DnsSdServiceList& services) override;
+
+  // Open cast channel on IO thread.

[mark a. foltz, 2017/06/28 22:43:13]

nit: Opens

[zhaobin, 2017/07/05 18:01:36]

Done.

+  // |service|: mDNS service description.
+  // |ip_endpoint|: cast channel's target IP endpoint.
+  void OpenChannelOnIOThread(const DnsSdService& service,
+                             const net::IPEndPoint& ip_endpoint);
+
+  // Invoked when opening cast channel on IO thread completes.
+  // |service|: mDNS service description.
+  // |channel_id|: channel id of newly created cast channel.
+  // |channel_error|: error encounted when opending cast channel.
+  void OnChannelOpenedOnIOThread(const DnsSdService& service,
+                                 int channel_id,
+                                 cast_channel::ChannelError channel_error);
+
+  // Invoked by |OnChannelOpenedOnIOThread| to post task on UI thread.
+  // |service|: mDNS service description.
+  // |channel_id|: channel id of newly created cast channel.
+  // |audio_only|: if cast channel is audio only or not.
+  void OnChannelOpenedOnUIThread(const DnsSdService& service,
+                                 int channel_id,
+                                 bool audio_only);
+
+  // Raw pointer to DnsSdRegistry singleton.

[mark a. foltz, 2017/06/28 22:43:13]

Can you comment about object lifetime here?  I assume the DnsSdRegistry lives as
long as the browser process?

[zhaobin, 2017/07/05 18:01:37]

Done.

+  DnsSdRegistry* dns_sd_registry_ = nullptr;
+
+  // DnsSdRegistry for test.
+  DnsSdRegistry* test_dns_sd_registry_ = nullptr;

[mark a. foltz, 2017/06/28 22:43:13]

Does this need to be held separately or can tests just reset |dns_sd_registry_|?

[zhaobin, 2017/07/05 18:01:37]

Yes, we can remove this and let SetDnsSdRegistryForTest() add observer for test
registry. If we do it this way, start/restart/stop unit test does not add much
value...

+
+  // Service list from current round of discovery.
+  DnsSdRegistry::DnsSdServiceList current_services_;
+
+  // Service managing creating and removing cast channels.
+  scoped_refptr<cast_channel::CastSocketService> cast_socket_service_;
+
+  THREAD_CHECKER(thread_checker_);
+
+  DISALLOW_COPY_AND_ASSIGN(CastMediaSinkService);
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MDNS_CAST_MEDIA_SINK_SERVICE_H_