Moved the fake input stream's processing onto the audio worker thread.

media/audio/fake_audio_input_stream.cc

Index: media/audio/fake_audio_input_stream.cc
diff --git a/media/audio/fake_audio_input_stream.cc b/media/audio/fake_audio_input_stream.cc
index 4632b258eda2abaf261bb7dba214ab6aba15d8bb..72b4c7baf0f07976d33ec25f41d65758362154bb 100644
--- a/media/audio/fake_audio_input_stream.cc
+++ b/media/audio/fake_audio_input_stream.cc
@@ -5,103 +5,17 @@
 #include "media/audio/fake_audio_input_stream.h"
 
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/command_line.h"
-#include "base/files/file.h"
-#include "base/lazy_instance.h"
+#include "base/files/file_path.h"
+#include "base/single_thread_task_runner.h"
+#include "base/time/time.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/base/audio_bus.h"
 #include "media/base/media_switches.h"
 
-using base::TimeTicks;
-using base::TimeDelta;
-
 namespace media {
 
-namespace {
-
-// These values are based on experiments for local-to-local
-// PeerConnection to demonstrate audio/video synchronization.
-const int kBeepDurationMilliseconds = 20;
-const int kBeepFrequency = 400;
-
-// Intervals between two automatic beeps.
-const int kAutomaticBeepIntervalInMs = 500;
-
-// Automatic beep will be triggered every |kAutomaticBeepIntervalInMs| unless
-// users explicitly call BeepOnce(), which will disable the automatic beep.
-class BeepContext {
- public:
-  BeepContext() : beep_once_(false), automatic_beep_(true) {}
-
-  void SetBeepOnce(bool enable) {
-    base::AutoLock auto_lock(lock_);
-    beep_once_ = enable;
-
-    // Disable the automatic beep if users explicit set |beep_once_| to true.
-    if (enable)
-      automatic_beep_ = false;
-  }
-  bool beep_once() const {
-    base::AutoLock auto_lock(lock_);
-    return beep_once_;
-  }
-  bool automatic_beep() const {
-    base::AutoLock auto_lock(lock_);
-    return automatic_beep_;
-  }
-
- private:
-  mutable base::Lock lock_;
-  bool beep_once_;
-  bool automatic_beep_;
-};
-
-// Opens |wav_filename|, reads it and loads it as a wav file. This function will
-// bluntly trigger CHECKs if we can't read the file or if it's malformed. The
-// caller takes ownership of the returned data. The size of the data is stored
-// in |read_length|.
-scoped_ptr<uint8[]> ReadWavFile(const base::FilePath& wav_filename,
-                                size_t* file_length) {
-  base::File wav_file(
-      wav_filename, base::File::FLAG_OPEN | base::File::FLAG_READ);
-  if (!wav_file.IsValid()) {
-    CHECK(false) << "Failed to read " << wav_filename.value() << " as input to "
-                 << "the fake device.";
-    return nullptr;
-  }
-
-  size_t wav_file_length = wav_file.GetLength();
-  CHECK_GT(wav_file_length, 0u)
-      << "Input file to fake device is empty: " << wav_filename.value();
-
-  uint8* wav_file_data = new uint8[wav_file_length];
-  size_t read_bytes = wav_file.Read(0, reinterpret_cast<char*>(wav_file_data),
-                                    wav_file_length);
-  if (read_bytes != wav_file_length) {
-    CHECK(false) << "Failed to read all bytes of " << wav_filename.value();
-    return nullptr;
-  }
-  *file_length = wav_file_length;
-  return scoped_ptr<uint8[]>(wav_file_data);
-}
-
-// Opens |wav_filename|, reads it and loads it as a Wav file. This function will
-// bluntly trigger CHECKs if we can't read the file or if it's malformed.
-scoped_ptr<media::WavAudioHandler> CreateWavAudioHandler(
-    const base::FilePath& wav_filename, const uint8* wav_file_data,
-    size_t wav_file_length, const AudioParameters& expected_params) {
-  base::StringPiece wav_data(reinterpret_cast<const char*>(wav_file_data),
-                             wav_file_length);
-  scoped_ptr<media::WavAudioHandler> wav_audio_handler(
-      new media::WavAudioHandler(wav_data));
-  return wav_audio_handler.Pass();
-}
-
-static base::LazyInstance<BeepContext> g_beep_context =
-    LAZY_INSTANCE_INITIALIZER;
-
-}  // namespace
-
 AudioInputStream* FakeAudioInputStream::MakeFakeStream(
     AudioManagerBase* manager,
     const AudioParameters& params) {
@@ -112,177 +26,47 @@ FakeAudioInputStream::FakeAudioInputStream(AudioManagerBase* manager,
                                            const AudioParameters& params)
     : audio_manager_(manager),
       callback_(NULL),
-      buffer_size_((params.channels() * params.bits_per_sample() *
-                    params.frames_per_buffer()) /
-                   8),
-      params_(params),
-      task_runner_(manager->GetTaskRunner()),
-      callback_interval_(base::TimeDelta::FromMilliseconds(
-          (params.frames_per_buffer() * 1000) / params.sample_rate())),
-      beep_duration_in_buffers_(kBeepDurationMilliseconds *
-                                params.sample_rate() /
-                                params.frames_per_buffer() /
-                                1000),
-      beep_generated_in_buffers_(0),
-      beep_period_in_frames_(params.sample_rate() / kBeepFrequency),
-      audio_bus_(AudioBus::Create(params)),
-      wav_file_read_pos_(0),
-      weak_factory_(this) {
+      fake_audio_provider_(manager->GetWorkerTaskRunner(), params) {
   DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
 }
 
-FakeAudioInputStream::~FakeAudioInputStream() {}
+FakeAudioInputStream::~FakeAudioInputStream() {
+  DCHECK(!callback_);
+}
 
 bool FakeAudioInputStream::Open() {
   DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
-  buffer_.reset(new uint8[buffer_size_]);
-  memset(buffer_.get(), 0, buffer_size_);
-  audio_bus_->Zero();
-
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kUseFileForFakeAudioCapture)) {
-    OpenInFileMode(base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
-        switches::kUseFileForFakeAudioCapture));
+      switches::kUseFileForFakeAudioCapture)) {
+    base::FilePath path_to_wav_file =
+        base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
+            switches::kUseFileForFakeAudioCapture);
+    CHECK(!path_to_wav_file.empty())
+        << "You must pass the file to use as argument to --"
+        << switches::kUseFileForFakeAudioCapture << ".";
+    fake_audio_provider_.OpenInFileMode(path_to_wav_file);
+  } else {
+    fake_audio_provider_.OpenInBeepMode();
   }
-
   return true;
 }
 
 void FakeAudioInputStream::Start(AudioInputCallback* callback)  {
   DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
-  DCHECK(!callback_);
   callback_ = callback;
-  last_callback_time_ = TimeTicks::Now();
-
-  task_runner_->PostDelayedTask(
-      FROM_HERE,
-      base::Bind(&FakeAudioInputStream::DoCallback, weak_factory_.GetWeakPtr()),
-      callback_interval_);
-}
-
-void FakeAudioInputStream::DoCallback() {
-  DCHECK(callback_);
-
-  const TimeTicks now = TimeTicks::Now();
-  base::TimeDelta next_callback_time =
-      last_callback_time_ + callback_interval_ * 2 - now;
-
-  // If we are falling behind, try to catch up as much as we can in the next
-  // callback.
-  if (next_callback_time < base::TimeDelta())
-    next_callback_time = base::TimeDelta();
-
-  if (PlayingFromFile()) {
-    PlayFile();
-  } else {
-    PlayBeep();
-  }
-
-  last_callback_time_ = now;
-
-  task_runner_->PostDelayedTask(
-      FROM_HERE,
-      base::Bind(&FakeAudioInputStream::DoCallback, weak_factory_.GetWeakPtr()),
-      next_callback_time);
-}
-
-void FakeAudioInputStream::OpenInFileMode(const base::FilePath& wav_filename) {
-  CHECK(!wav_filename.empty())
-      << "You must pass the file to use as argument to --"
-      << switches::kUseFileForFakeAudioCapture << ".";
-
-  // Read the file, and put its data in a scoped_ptr so it gets deleted later.
-  size_t file_length = 0;
-  wav_file_data_ = ReadWavFile(wav_filename, &file_length);
-  wav_audio_handler_ = CreateWavAudioHandler(
-      wav_filename, wav_file_data_.get(), file_length, params_);
-
-  // Hook us up so we pull in data from the file into the converter. We need to
-  // modify the wav file's audio parameters since we'll be reading small slices
-  // of it at a time and not the whole thing (like 10 ms at a time).
-  AudioParameters file_audio_slice(
-      wav_audio_handler_->params().format(),
-      wav_audio_handler_->params().channel_layout(),
-      wav_audio_handler_->params().sample_rate(),
-      wav_audio_handler_->params().bits_per_sample(),
-      params_.frames_per_buffer());
-
-  file_audio_converter_.reset(
-      new AudioConverter(file_audio_slice, params_, false));
-  file_audio_converter_->AddInput(this);
-}
-
-bool FakeAudioInputStream::PlayingFromFile() {
-  return wav_audio_handler_.get() != nullptr;
-}
-
-void FakeAudioInputStream::PlayFile() {
-  // Stop playing if we've played out the whole file.
-  if (wav_audio_handler_->AtEnd(wav_file_read_pos_))
-    return;
-
-  file_audio_converter_->Convert(audio_bus_.get());
-  callback_->OnData(this, audio_bus_.get(), buffer_size_, 1.0);
-}
-
-void FakeAudioInputStream::PlayBeep() {
-  // Accumulate the time from the last beep.
-  interval_from_last_beep_ += TimeTicks::Now() - last_callback_time_;
-
-  memset(buffer_.get(), 0, buffer_size_);
-  bool should_beep = false;
-  {
-    BeepContext* beep_context = g_beep_context.Pointer();
-    if (beep_context->automatic_beep()) {
-      base::TimeDelta delta = interval_from_last_beep_ -
-          TimeDelta::FromMilliseconds(kAutomaticBeepIntervalInMs);
-      if (delta > base::TimeDelta()) {
-        should_beep = true;
-        interval_from_last_beep_ = delta;
-      }
-    } else {
-      should_beep = beep_context->beep_once();
-      beep_context->SetBeepOnce(false);
-    }
-  }
-
-  // If this object was instructed to generate a beep or has started to
-  // generate a beep sound.
-  if (should_beep || beep_generated_in_buffers_) {
-    // Compute the number of frames to output high value. Then compute the
-    // number of bytes based on channels and bits per channel.
-    int high_frames = beep_period_in_frames_ / 2;
-    int high_bytes = high_frames * params_.bits_per_sample() *
-        params_.channels() / 8;
-
-    // Separate high and low with the same number of bytes to generate a
-    // square wave.
-    int position = 0;
-    while (position + high_bytes <= buffer_size_) {
-      // Write high values first.
-      memset(buffer_.get() + position, 128, high_bytes);
-      // Then leave low values in the buffer with |high_bytes|.
-      position += high_bytes * 2;
-    }
-
-    ++beep_generated_in_buffers_;
-    if (beep_generated_in_buffers_ >= beep_duration_in_buffers_)
-      beep_generated_in_buffers_ = 0;
-  }
-
-  audio_bus_->FromInterleaved(
-      buffer_.get(), audio_bus_->frames(), params_.bits_per_sample() / 8);
-  callback_->OnData(this, audio_bus_.get(), buffer_size_, 1.0);
+  fake_audio_provider_.Start(base::Bind(
+      &FakeAudioInputStream::OnMoreInputData, base::Unretained(this)));
 }
 
 void FakeAudioInputStream::Stop() {
   DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
-  weak_factory_.InvalidateWeakPtrs();
+  fake_audio_provider_.Stop();
   callback_ = NULL;
 }
 
 void FakeAudioInputStream::Close() {
   DCHECK(audio_manager_->GetTaskRunner()->BelongsToCurrentThread());
+  DCHECK(!callback_);
   audio_manager_->ReleaseInputStream(this);
 }
 
@@ -313,20 +97,15 @@ bool FakeAudioInputStream::GetAutomaticGainControl() {
   return false;
 }
 
-// static
-void FakeAudioInputStream::BeepOnce() {
-  BeepContext* beep_context = g_beep_context.Pointer();
-  beep_context->SetBeepOnce(true);
+void FakeAudioInputStream::OnMoreInputData(
+    AudioBus* audio_bus, int buffer_size) {
+  DCHECK(audio_manager_->GetWorkerTaskRunner()->BelongsToCurrentThread());
+  DCHECK(callback_);
+  callback_->OnData(this, audio_bus, buffer_size, 1.0);
 }
 
-double FakeAudioInputStream::ProvideInput(AudioBus* audio_bus_into_converter,
-                                          base::TimeDelta buffer_delay) {
-  // Unfilled frames will be zeroed by CopyTo.
-  size_t bytes_written;
-  wav_audio_handler_->CopyTo(audio_bus_into_converter, wav_file_read_pos_,
-                             &bytes_written);
-  wav_file_read_pos_ += bytes_written;
-  return 1.0;
-};
+void FakeAudioInputStream::BeepOnce() {
+  FakeAudioProvider::BeepOnce();
+}
 
 }  // namespace media