ChromeOS: enable pinning stream output routing for webapp request [extracted from 2516813002]

media/audio/cras/cras_unified.cc

 // Copyright 2013 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 "media/audio/cras/cras_unified.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/strings/string_number_conversions.h"
 #include "media/audio/cras/audio_manager_cras.h"
 
 namespace media {
 
 // Overview of operation:
 // 1) An object of CrasUnifiedStream is created by the AudioManager
 // factory: audio_man->MakeAudioStream().
 // 2) Next some thread will call Open(), at that point a client is created and
 // configured for the correct format and sample rate.
 // 3) Then Start(source) is called and a stream is added to the CRAS client
@@ skipping 24 matching lines @@
 //          |  Remove stream                    |
 //          |<----------------------------------|
 //          |                                   |
 //
 // For Unified streams the Chrome client is notified whenever buffer_frames have
 // been captured.  For Output streams the client is notified a few milliseconds
 // before the hardware buffer underruns and fills the buffer with another block
 // of audio.
 
 CrasUnifiedStream::CrasUnifiedStream(const AudioParameters& params,
-                                     AudioManagerCras* manager)
+                                     AudioManagerCras* manager,
+                                     const std::string& device_id)
     : client_(NULL),
       stream_id_(0),
       params_(params),
       bytes_per_frame_(0),
       is_playing_(false),
       volume_(1.0),
       manager_(manager),
       source_callback_(NULL),
-      stream_direction_(CRAS_STREAM_OUTPUT) {
+      stream_direction_(CRAS_STREAM_OUTPUT),
+      pin_device_(NO_DEVICE) {
   DCHECK(manager_);
   DCHECK_GT(params_.channels(), 0);
 
   output_bus_ = AudioBus::Create(params);

[tommi (sloooow) - chröme, 2017/01/25 22:05:28]

initialize in the initializer list?

[Qiang(Joe) Xu, 2017/01/25 22:50:18]

Done.

+  if (!manager_->IsDefault(device_id, false)) {
+    uint64_t cras_node_id;
+    base::StringToUint64(device_id, &cras_node_id);
+    pin_device_ = dev_index_of(cras_node_id);

[tommi (sloooow) - chröme, 2017/01/25 22:05:28]

in order to make pin_device_ const, you could extract this part out to a little
helper function:

namespace media {
namespace {
int GetDevicePin(AudioManagerCras* manager, const std::string& device_id) {
  if (manager->IsDefault(device_id, false)) {
    uint64_t cras_node_id;
    base::StringToUint64(device_id, &cras_node_id);
    return dev_index_of(cras_node_id);
  }
  return NO_DEVICE;
}
}  // namespace

CrasUnifiedStream::CrasUnifiedStream(...)
    : client_(NULL),
      ...
      pin_device_(GetDevicePin(manager, device_id)) {
...

[Qiang(Joe) Xu, 2017/01/25 22:50:18]

Done.

+  }
 }
 
 CrasUnifiedStream::~CrasUnifiedStream() {
   DCHECK(!is_playing_);
 }
 
 bool CrasUnifiedStream::Open() {
   // Sanity check input values.
   if (params_.sample_rate() <= 0) {
     LOG(WARNING) << "Unsupported audio frequency.";
@@ skipping 110 matching lines @@
     callback->OnError(this);
     cras_audio_format_destroy(audio_format);
     return;
   }
 
   // Before starting the stream, save the number of bytes in a frame for use in
   // the callback.
   bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
 
   // Adding the stream will start the audio callbacks requesting data.
-  if (cras_client_add_stream(client_, &stream_id_, stream_params) < 0) {
-    LOG(WARNING) << "Failed to add the stream";
+  if (cras_client_add_pinned_stream(client_, pin_device_, &stream_id_,
+                                    stream_params)) {
+    LOG(WARNING) << "Failed to add the stream.";
     callback->OnError(this);
     cras_audio_format_destroy(audio_format);
     cras_client_stream_params_destroy(stream_params);
     return;
   }
 
   // Set initial volume.
   cras_client_set_stream_volume(client_, stream_id_, volume_);
 
   // Done with config params.
@@ skipping 94 matching lines @@
   return frames_filled;
 }
 
 void CrasUnifiedStream::NotifyStreamError(int err) {
   // This will remove the stream from the client.
   if (source_callback_)
     source_callback_->OnError(this);
 }
 
 }  // namespace media