Tab Audio Capture: Browser-side connect/disconnect functionality.

content/browser/renderer_host/media/audio_renderer_host.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/media/audio_renderer_host.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/browser/browser_main_loop.h"
+#include "content/browser/renderer_host/media/audio_mirroring_manager.h"
 #include "content/browser/renderer_host/media/audio_sync_reader.h"
 #include "content/common/media/audio_messages.h"
 #include "content/public/browser/media_observer.h"
 #include "media/audio/shared_memory_util.h"
 #include "media/base/audio_bus.h"
 #include "media/base/limits.h"
 
 using media::AudioBus;
 
 namespace content {
 
 struct AudioRendererHost::AudioEntry {
   AudioEntry();
   ~AudioEntry();
 
   // The AudioOutputController that manages the audio stream.
   scoped_refptr<media::AudioOutputController> controller;
 
   // The audio stream ID.
   int stream_id;
 
+  // The routing ID of the source render view.
+  int render_view_id;
+
   // Shared memory for transmission of the audio data.
   base::SharedMemory shared_memory;
 
   // The synchronous reader to be used by the controller. We have the
   // ownership of the reader.
   scoped_ptr<media::AudioOutputController::SyncReader> reader;
 
   // Set to true after we called Close() for the controller.
   bool pending_close;
 };
 
 AudioRendererHost::AudioEntry::AudioEntry()
     : stream_id(0),
+      render_view_id(MSG_ROUTING_NONE),
       pending_close(false) {
 }
 
 AudioRendererHost::AudioEntry::~AudioEntry() {}
 
 ///////////////////////////////////////////////////////////////////////////////
 // AudioRendererHost implementations.
 AudioRendererHost::AudioRendererHost(
-    media::AudioManager* audio_manager, MediaObserver* media_observer)
-    : audio_manager_(audio_manager),
+    int render_process_id,
+    media::AudioManager* audio_manager,
+    AudioMirroringManager* mirroring_manager,
+    MediaObserver* media_observer)
+    : render_process_id_(render_process_id),
+      audio_manager_(audio_manager),
+      mirroring_manager_(mirroring_manager),
       media_observer_(media_observer) {
+  DCHECK(audio_manager_);
+  DCHECK(mirroring_manager_);
 }
 
 AudioRendererHost::~AudioRendererHost() {
   DCHECK(audio_entries_.empty());
 }
 
 void AudioRendererHost::OnChannelClosing() {
   BrowserMessageFilter::OnChannelClosing();
 
   // Since the IPC channel is gone, close all requested audio streams.
@@ skipping 207 matching lines @@
   // If we have created the controller successfully, create an entry and add it
   // to the map.
   entry->stream_id = stream_id;
   audio_entries_.insert(std::make_pair(stream_id, entry.release()));
   if (media_observer_)
     media_observer_->OnSetAudioStreamStatus(this, stream_id, "created");
 }
 
 void AudioRendererHost::OnAssociateStreamWithProducer(int stream_id,
                                                       int render_view_id) {
-  // TODO(miu): Will use render_view_id in upcoming change.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
   DVLOG(1) << "AudioRendererHost@" << this
            << "::OnAssociateStreamWithProducer(stream_id=" << stream_id
            << ", render_view_id=" << render_view_id << ")";
+
+  AudioEntry* const entry = LookupById(stream_id);
+  if (!entry) {
+    SendErrorMessage(stream_id);
+    return;
+  }
+
+  if (entry->render_view_id == render_view_id)
+    return;  // No change.

[Chris Rogers, 2013/01/09 21:18:44]

comment is obvious - adds little value

[miu, 2013/01/10 21:23:26]

Done.

+
+  mirroring_manager_->RemoveDiverter(
+      render_process_id_, entry->render_view_id, entry->controller);
+  entry->render_view_id = render_view_id;
+  mirroring_manager_->AddDiverter(
+      render_process_id_, entry->render_view_id, entry->controller);

[Chris Rogers, 2013/01/09 21:18:44]

We certainly don't have to do this now, but struct AudioRendererHost::AudioEntry
has been begging to be made into a full-fledged class to help relieve the burden
on implementation details now handled in AudioRendererHost.  It could handle
some of the nitty-gritty work relating to setting up the shared-memory and
SyncSocket.   It could also handle the logic you're adding in lines 308:315

maybe worth thinking about for future cleanup, a TODO, etc.

[miu, 2013/01/10 21:23:26]

Agreed.  There's also other clean-up and even bug fixes I've noticed are needed
in this area.  For example, the complex "pending_close" scheme should be
unnecessary.  This CL's big enough right now, so this is definitely future
cleanup territory.

 }
 
 void AudioRendererHost::OnPlayStream(int stream_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   AudioEntry* entry = LookupById(stream_id);
   if (!entry) {
     SendErrorMessage(stream_id);
     return;
   }
@@ skipping 71 matching lines @@
   for (AudioEntryMap::iterator i = audio_entries_.begin();
        i != audio_entries_.end(); ++i) {
     CloseAndDeleteStream(i->second);
   }
 }
 
 void AudioRendererHost::CloseAndDeleteStream(AudioEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   if (!entry->pending_close) {
+    mirroring_manager_->RemoveDiverter(
+        render_process_id_, entry->render_view_id, entry->controller);
     entry->controller->Close(
         base::Bind(&AudioRendererHost::DeleteEntry, this, entry));
     entry->pending_close = true;
   }
 }
 
 void AudioRendererHost::DeleteEntry(AudioEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   // Delete the entry when this method goes out of scope.
@@ skipping 42 matching lines @@
   return NULL;
 }
 
 media::AudioOutputController* AudioRendererHost::LookupControllerByIdForTesting(
     int stream_id) {
   AudioEntry* const entry = LookupById(stream_id);
   return entry ? entry->controller : NULL;
 }
 
 }  // namespace content