Non-Local Join for Media Router and Presentation API

chrome/browser/media/router/media_router_mojo_impl.cc

Index: chrome/browser/media/router/media_router_mojo_impl.cc
diff --git a/chrome/browser/media/router/media_router_mojo_impl.cc b/chrome/browser/media/router/media_router_mojo_impl.cc
index ab4249eb9c3f73eae96de1a4854df222f74f11fe..fc89f58a16d7239abba923b3e0ece3281dec3c43 100644
--- a/chrome/browser/media/router/media_router_mojo_impl.cc
+++ b/chrome/browser/media/router/media_router_mojo_impl.cc
@@ -74,12 +74,17 @@ MediaRouterMojoImpl::MediaRouterMediaRoutesObserver::
 ~MediaRouterMediaRoutesObserver() {
 }
 
+MediaRouterMojoImpl::MediaRoutesQuery::MediaRoutesQuery() = default;
+
+MediaRouterMojoImpl::MediaRoutesQuery::~MediaRoutesQuery() = default;
+
 MediaRouterMojoImpl::MediaSinksQuery::MediaSinksQuery() = default;
 
 MediaRouterMojoImpl::MediaSinksQuery::~MediaSinksQuery() = default;
 
 void MediaRouterMojoImpl::MediaRouterMediaRoutesObserver::OnRoutesUpdated(
-    const std::vector<media_router::MediaRoute>& routes) {
+    const std::vector<media_router::MediaRoute>& routes,
+    const std::vector<media_router::MediaRoute::Id>& joinable_route_ids) {
   bool has_local_display_route =
       std::find_if(routes.begin(), routes.end(),
                    [](const media_router::MediaRoute& route) {
@@ -192,6 +197,14 @@ void MediaRouterMojoImpl::OnSinksReceived(
   DCHECK(thread_checker_.CalledOnValidThread());
 
   DVLOG_WITH_INSTANCE(1) << "OnSinksReceived";
+  auto it = sinks_queries_.find(media_source);
+  if (it == sinks_queries_.end() ||
+      !(it->second->observers.might_have_observers())) {
+    DVLOG_WITH_INSTANCE(1)
+        << "Received sink list without any active observers: " << media_source;
+    return;
+  }
+
   std::vector<MediaSink> sinks_converted;
   sinks_converted.reserve(sinks.size());
 
@@ -199,32 +212,40 @@ void MediaRouterMojoImpl::OnSinksReceived(
     sinks_converted.push_back(sinks[i].To<MediaSink>());
   }
 
-  auto it = sinks_queries_.find(media_source);
-  if (it == sinks_queries_.end() ||
-      !(it->second->observers.might_have_observers())) {
-    DVLOG_WITH_INSTANCE(1)
-        << "Received sink list without any active observers: " << media_source;
-  } else {
-    FOR_EACH_OBSERVER(MediaSinksObserver, it->second->observers,
-                      OnSinksReceived(sinks_converted));
-  }
+  FOR_EACH_OBSERVER(MediaSinksObserver, it->second->observers,
+                    OnSinksReceived(sinks_converted));
 }
 
 void MediaRouterMojoImpl::OnRoutesUpdated(
-    mojo::Array<interfaces::MediaRoutePtr> routes) {
+    const mojo::String& media_source,
+    mojo::Array<interfaces::MediaRoutePtr> routes,
+    mojo::Array<mojo::String> joinable_route_ids) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   DVLOG_WITH_INSTANCE(1) << "OnRoutesUpdated";
+  auto it = routes_queries_.find(media_source);
+  if (it == routes_queries_.end() ||
+      !(it->second->observers.might_have_observers())) {
+    DVLOG_WITH_INSTANCE(1)
+        << "Received route list without any active observers: " << media_source;
+    return;
+  }
 
   std::vector<MediaRoute> routes_converted;
   routes_converted.reserve(routes.size());
 
-  for (size_t i = 0; i < routes.size(); ++i) {
+  std::vector<MediaRoute::Id> joinable_routes_converted;
+  joinable_routes_converted.reserve(joinable_route_ids.size());
+
+  for (size_t i = 0; i < routes.size(); ++i)
     routes_converted.push_back(routes[i].To<MediaRoute>());
-  }
 
-  FOR_EACH_OBSERVER(MediaRoutesObserver, routes_observers_,
-                    OnRoutesUpdated(routes_converted));
+  for (size_t i = 0; i < joinable_route_ids.size(); ++i)
+    joinable_routes_converted.push_back(joinable_route_ids[i]);
+
+  FOR_EACH_OBSERVER(MediaRoutesObserver, it->second->observers,
+                    OnRoutesUpdated(routes_converted,
+                                    joinable_routes_converted));
 }
 
 void MediaRouterMojoImpl::RouteResponseReceived(
@@ -314,6 +335,30 @@ void MediaRouterMojoImpl::JoinRoute(
                         callbacks));
 }
 
+void MediaRouterMojoImpl::JoinRouteByRouteId(
+    const MediaSource::Id& source_id,
+    const MediaRoute::Id& route_id,
+    const GURL& origin,
+    content::WebContents* web_contents,
+    const std::vector<MediaRouteResponseCallback>& callbacks) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (!origin.is_valid()) {
+    DVLOG_WITH_INSTANCE(1) << "Invalid origin: " << origin;
+    for (const MediaRouteResponseCallback& callback : callbacks)
+      callback.Run(nullptr, "", "Invalid origin");
+    return;
+  }
+
+  int tab_id = SessionTabHelper::IdForTab(web_contents);
+  std::string presentation_id("non-local-join_");

[mark a. foltz, 2015/12/03 19:24:23]

What is this for - shouldn't the route_id already have a presentation_id?

[matt.boetger, 2015/12/15 19:21:20]

Since this is non-local, the route_id contains the cast session id (since there
is no presentation id) - this is used to join.  Since we are going to the
connectRouteByRouteId we can remove this.

+  presentation_id += route_id;
+  RunOrDefer(base::Bind(&MediaRouterMojoImpl::DoJoinRoute,

[mark a. foltz, 2015/12/03 19:24:23]

I'm not sure DoJoinRoute is the right API to call here since we are joining a
route without an associated presentation (at least that the caller knows about.)
 Or is the fake presentation id a way to re-use the existing API?

[matt.boetger, 2015/12/15 19:21:20]

Yes, the fake presentation id was a way to re-use the existing API.  Since we
are going to the "connectRouteByRouteId" method on the media router - we can
remove this.

+                        base::Unretained(this), source_id, presentation_id,
+                        origin.is_empty() ? "" : origin.spec(), tab_id,
+                        callbacks));
+}
+
 void MediaRouterMojoImpl::CloseRoute(const MediaRoute::Id& route_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ -430,24 +475,38 @@ void MediaRouterMojoImpl::UnregisterMediaSinksObserver(
 void MediaRouterMojoImpl::RegisterMediaRoutesObserver(
     MediaRoutesObserver* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!routes_observers_.HasObserver(observer));
+  const MediaSource::Id source_id = observer->source_id();
+  auto* routes_query = routes_queries_.get(source_id);
+  if (!routes_query) {
+    routes_query = new MediaRoutesQuery;
+    routes_queries_.add(source_id, make_scoped_ptr(routes_query));
+  } else {
+    DCHECK(!routes_query->observers.HasObserver(observer));
+  }
 
+  routes_query->observers.AddObserver(observer);
   SetWakeReason(MediaRouteProviderWakeReason::START_OBSERVING_MEDIA_ROUTES);
   RunOrDefer(base::Bind(&MediaRouterMojoImpl::DoStartObservingMediaRoutes,
-                        base::Unretained(this)));
-  routes_observers_.AddObserver(observer);
+                        base::Unretained(this), source_id));
 }
 
 void MediaRouterMojoImpl::UnregisterMediaRoutesObserver(
     MediaRoutesObserver* observer) {
-  if (!routes_observers_.HasObserver(observer))
+  const MediaSource::Id source_id = observer->source_id();
+  auto* routes_query = routes_queries_.get(source_id);
+  if (!routes_query || !routes_query->observers.HasObserver(observer)) {
     return;
+  }
 
-  routes_observers_.RemoveObserver(observer);
-  if (!routes_observers_.might_have_observers()) {
+  // If we are removing the final observer for the source, then stop
+  // observing routes for it.
+  // might_have_observers() is reliable here on the assumption that this call
+  // is not inside the ObserverList iteration.
+  routes_query->observers.RemoveObserver(observer);
+  if (!routes_query->observers.might_have_observers()) {
     SetWakeReason(MediaRouteProviderWakeReason::STOP_OBSERVING_MEDIA_ROUTES);
     RunOrDefer(base::Bind(&MediaRouterMojoImpl::DoStopObservingMediaRoutes,
-                          base::Unretained(this)));
+                          base::Unretained(this), source_id));
   }
 }
 
@@ -724,14 +783,36 @@ void MediaRouterMojoImpl::DoStopObservingMediaSinks(
   sinks_queries_.erase(source_id);
 }
 
-void MediaRouterMojoImpl::DoStartObservingMediaRoutes() {
+void MediaRouterMojoImpl::DoStartObservingMediaRoutes(
+    const MediaSource::Id& source_id) {
   DVLOG_WITH_INSTANCE(1) << "DoStartObservingMediaRoutes";
-  media_route_provider_->StartObservingMediaRoutes();
+
+  // No need to call MRPM if all observers have been removed in the meantime.
+  auto* routes_query = routes_queries_.get(source_id);

[mark a. foltz, 2015/12/03 19:24:23]

This pattern is repeated a couple of times - please factor out methods
HasRoutesObserver(source_id) and HasSinksObserver(source_id)

[matt.boetger, 2015/12/15 19:21:20]

Done.

+  if (!routes_query || !routes_query->observers.might_have_observers()) {
+    return;
+  }
+
+  DVLOG_WITH_INSTANCE(1) << "MRPM.StartObservingMediaRoutes: " << source_id;
+  media_route_provider_->StartObservingMediaRoutes(source_id);
+  routes_query->is_active = true;
 }
 
-void MediaRouterMojoImpl::DoStopObservingMediaRoutes() {
+void MediaRouterMojoImpl::DoStopObservingMediaRoutes(
+    const MediaSource::Id& source_id) {
   DVLOG_WITH_INSTANCE(1) << "DoStopObservingMediaRoutes";
-  media_route_provider_->StopObservingMediaRoutes();
+
+  auto* routes_query = routes_queries_.get(source_id);
+  // No need to call MRPM if observers have been added in the meantime,
+  // or StopObservingMediaSinks has already been called.
+  if (!routes_query || !routes_query->is_active ||
+      routes_query->observers.might_have_observers()) {
+    return;
+  }
+
+  DVLOG_WITH_INSTANCE(1) << "MRPM.StopObservingMediaRoutes: " << source_id;
+  media_route_provider_->StopObservingMediaRoutes(source_id);
+  routes_queries_.erase(source_id);
 }
 
 void MediaRouterMojoImpl::EnqueueTask(const base::Closure& closure) {