[Media Router] Add DialMediaSinkService and DeviceDescriptionService

chrome/browser/media/router/discovery/dial/dial_media_sink_service.cc

+// 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.
+
+#include "chrome/browser/media/router/discovery/dial/dial_media_sink_service.h"
+
+#include "chrome/browser/media/router/discovery/dial/dial_device_data.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/url_request/url_request_context_getter.h"
+
+using content::BrowserThread;
+
+namespace {
+// Time interval when media sink service sends sinks to MRP.
+const int kFetchCompleteTimeoutSecs = 3;
+}
+
+namespace media_router {
+
+DialMediaSinkService::DialMediaSinkService(
+    const OnSinksDiscoveredCallback& callback,
+    content::BrowserContext* browser_context,
+    net::URLRequestContextGetter* request_context)
+    : MediaSinkService(callback), browser_context_(browser_context) {

[imcheng, 2017/04/26 22:52:16]

browser_context_ not used?

[zhaobin, 2017/04/27 01:41:20]

Done.

+  DCHECK_CURRENTLY_ON(BrowserThread::IO);

[imcheng, 2017/04/26 22:52:16]

The constructor will be invoked by MediaRouter in the UI thread, right?

[zhaobin, 2017/04/27 01:41:20]

Plan to create this in IO thread. Will update
https://codereview.chromium.org/2837363002/

if (impl->enable_browser_side_discovery_)
  impl->StartBrowserSideDiscovery();

will become:

if (impl->enable_browser_side_discovery_) {
...
content::BrowserThread::PostTask(
    content::BrowserThread::IO, FROM_HERE,
    base::Bind(&MediaRouterMojoImpl::StartBrowserSideDiscovery,
               base::Unretained(impl), ...));
}

[imcheng, 2017/04/27 19:21:32]

Hmm, I don't think that will work. MediaRouterMojoImpl isn't thread safe, and we
are passing it as a raw pointer to a different thread. We would have to make
MediaRouterMojoImpl inherit RefCountedThreadSafe for that to work. I think I
would prefer to keep MediaRouterMojoImpl as-is (i.e. always operating on UI
thread) and make MediaSinkService inherit RefCountedThreadSafe and do the
thread-hopping between IO and UI thread. This is ok for now but we might have to
revise it in https://codereview.chromium.org/2837363002/. Let's chat offline so
we are same page about the threading model?

+  request_context_ = request_context;

[imcheng, 2017/04/26 22:52:16]

Can this go in the initializer?

[zhaobin, 2017/04/27 01:41:20]

Done.

+
+  DCHECK(request_context_);
+}
+
+DialMediaSinkService::~DialMediaSinkService() {}
+
+void DialMediaSinkService::Start() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  dial_registry()->RegisterObserver(this);
+  dial_registry()->OnListenerAdded();
+}
+
+void DialMediaSinkService::Stop() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  dial_registry()->UnregisterObserver(this);
+}
+
+void DialMediaSinkService::AddSinkQuery(MediaSinksObserver* observer) {
+  // TODO(crbug.com/687375): Implement DIAL sink query.
+  NOTIMPLEMENTED();
+}
+
+void DialMediaSinkService::RemoveSinkQuery(MediaSinksObserver* observer) {
+  // TODO(crbug.com/687375): Implement DIAL sink query.
+  NOTIMPLEMENTED();
+}
+
+DialRegistry* DialMediaSinkService::dial_registry() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  return DialRegistry::GetInstance();
+}
+
+DeviceDescriptionService* DialMediaSinkService::GetDescriptionService() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (!description_service_.get()) {
+    description_service_.reset(new DeviceDescriptionService(
+        base::Bind(&DialMediaSinkService::OnDeviceDescriptionAvailable,
+                   base::Unretained(this)),
+        base::Bind(&DialMediaSinkService::OnDeviceDescriptionError,
+                   base::Unretained(this))));
+  }
+  return description_service_.get();
+}
+
+void DialMediaSinkService::OnDialDeviceEvent(
+    const DialRegistry::DeviceList& devices) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DVLOG(2) << "DialMediaSinkService::OnDialDeviceEvent found " << devices.size()
+           << " devices";
+
+  // Add a finish timer.
+  finish_timer_.reset(new base::OneShotTimer());
+  base::TimeDelta finish_delay =
+      base::TimeDelta::FromSeconds(kFetchCompleteTimeoutSecs);
+  finish_timer_->Start(FROM_HERE, finish_delay, this,
+                       &DialMediaSinkService::OnFetchCompleted);
+
+  current_sinks_.clear();
+  current_devices_ = devices;
+
+  GetDescriptionService()->GetDeviceDescriptions(devices,
+                                                 request_context_.get());
+}
+
+void DialMediaSinkService::OnDialError(DialRegistry::DialErrorCode type) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DVLOG(2) << "OnDialError [DialErrorCode]: " << static_cast<int>(type);
+}
+
+void DialMediaSinkService::OnDeviceDescriptionAvailable(
+    const DialDeviceData& device_data,
+    const ParsedDialDeviceDescription& description_data) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (!base::ContainsValue(current_devices_, device_data)) {
+    DVLOG(2) << "Device data not found in current device data list...";
+    return;
+  }
+
+  MediaSink sink(description_data.unique_id, description_data.friendly_name,

[imcheng, 2017/04/26 22:52:16]

Note this "sink" will have a different ID when it is sent to the extension,
because it derives a different sink ID using the given sink ID. Right now it is
not a problem because this sink is never used within the browser. Just something
to keep in mind.

[zhaobin, 2017/04/27 01:41:20]

Added a comment.

+                 MediaSink::IconType::GENERIC);
+  DialSinkExtraData extra_data;
+  extra_data.app_url = description_data.app_url;
+  extra_data.model_name = description_data.model_name;
+  std::string ip_address = device_data.device_description_url().host();
+  if (!extra_data.ip_address.AssignFromIPLiteral(ip_address)) {
+    DVLOG(1) << "Invalid ip_address: " << ip_address;
+    return;
+  }
+
+  current_sinks_.insert(MediaSinkInternal(sink, extra_data));
+
+  if (finish_timer_)
+    return;
+
+  // Start fetch timer again if device description comes back after
+  // |finish_timer_| fires.
+  base::TimeDelta finish_delay =
+      base::TimeDelta::FromSeconds(kFetchCompleteTimeoutSecs);
+  finish_timer_.reset(new base::OneShotTimer());
+  finish_timer_->Start(FROM_HERE, finish_delay, this,
+                       &DialMediaSinkService::OnFetchCompleted);
+}
+
+void DialMediaSinkService::OnDeviceDescriptionError(
+    const DialDeviceData& device,
+    const std::string& error_message) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DVLOG(2) << "OnDescriptionFetchesError [message]: " << error_message;
+}
+
+void DialMediaSinkService::OnFetchCompleted() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(!sink_discovery_callback_.is_null());
+
+  finish_timer_.reset();
+
+  auto sinks = current_sinks_;
+  if (sinks == mrp_sinks_) {
+    DVLOG(2) << "No update to sink list.";
+    return;
+  }
+
+  DVLOG(2) << "Send sinks to media router, [size]: " << sinks.size();
+  sink_discovery_callback_.Run(
+      std::vector<MediaSinkInternal>(sinks.begin(), sinks.end()));
+  mrp_sinks_ = std::move(sinks);
+}
+
+}  // namespace media_router