Audio output debug recording.

media/audio/audio_debug_recording_manager.h

+// 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.
+
+#ifndef MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_MANAGER_H_
+#define MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_MANAGER_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "media/audio/audio_debug_recording_helper.h"
+#include "media/audio/audio_file_writer.h"
+#include "media/base/audio_parameters.h"
+#include "media/base/media_export.h"
+
+namespace base {
+class FilePath;
+class SingleThreadTaskRunner;
+}
+
+namespace media {
+
+class AudioDebugRecordingHelper;
+
+// A manager for audio debug recording that handles registration of data
+// sources and hands them a recorder (AudioDebugRecordingHelper) to feed data
+// to. The recorder will unregister with the manager automatically when deleted.
+// When debug recording is enabled, it is enabled on all recorders and
+// constructs a unique file name for each recorder by using a running ID.
+class MEDIA_EXPORT AudioDebugRecordingManager {

[o1ka, 2017/02/09 13:04:03]

Can we have a description or pseudo-graphic of the whole debug recording
infrastructure and objects ownership here?

[Henrik Grunell, 2017/02/10 09:00:56]

That's a good idea. I created a diagram doc to assist the CL description, but
it's of course best to have maintainable documentation close to the source code.
I wrote up a simplified diagram.

+ public:
+  AudioDebugRecordingManager(
+      CreateAudioFileWriterCallback create_audio_file_writer_callback,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  virtual ~AudioDebugRecordingManager();
+
+  // Enables and disables debug recording.
+  void EnableDebugRecording(const base::FilePath& base_file_name);
+  void DisableDebugRecording();
+
+  // Registers a source and returns a wrapped recorder. |file_name_extension| is
+  // added to the base filename, along with a unique running ID.
+  std::unique_ptr<AudioDebugRecorder> RegisterDebugRecordingSource(
+      const std::string& file_name_extension,
+      const AudioParameters& params);
+
+ protected:
+  // Creates a AudioDebugRecordingHelper. Overridden by test.
+  virtual std::unique_ptr<AudioDebugRecordingHelper>
+  CreateAudioDebugRecordingHelper(
+      const AudioParameters& params,
+      const CreateAudioFileWriterCallback& create_audio_file_writer_callback,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      base::OnceClosure on_destruction_closure);
+
+  // Callback for creating AudioFileWriter objects.
+  const CreateAudioFileWriterCallback create_audio_file_writer_callback_;
+
+  // The task runner this class lives on. Also handed to
+  // AudioDebugRecordingHelpers.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(AudioDebugRecordingManagerTest,
+                           RegisterAutomaticUnregisterAtDelete);
+  FRIEND_TEST_ALL_PREFIXES(AudioDebugRecordingManagerTest,
+                           RegisterEnableDisable);
+  FRIEND_TEST_ALL_PREFIXES(AudioDebugRecordingManagerTest,
+                           EnableRegisterDisable);
+
+  // Map type from source id to recorder and its filename extension.
+  using DebugRecordingHelperMap =
+      std::map<int, std::pair<AudioDebugRecordingHelper*, std::string>>;
+
+  // Unregisters a source.
+  void UnregisterDebugRecordingSource(int id);
+
+  // Recorders, one per source.
+  DebugRecordingHelperMap debug_recording_helpers_;
+
+  // The base file name for debug recording files. If this is non-empty, debug
+  // recording is enabled.
+  base::FilePath debug_recording_base_file_name_;
+
+  base::WeakPtrFactory<AudioDebugRecordingManager> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(AudioDebugRecordingManager);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_MANAGER_H_