1// Copyright 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef MEDIA_AUDIO_AUDIO_LOGGING_H_
6#define MEDIA_AUDIO_AUDIO_LOGGING_H_
7
8#include <string>
9
10#include "base/memory/scoped_ptr.h"
11
12namespace media {
13class AudioParameters;
14
15// AudioLog logs state information about an active audio component.  Each method
16// takes a |component_id| along with method specific information.  Its methods
17// are safe to call from any thread.
18class AudioLog {
19 public:
20  virtual ~AudioLog() {}
21
22  // Called when an audio component is created.  |params| are the parameters of
23  // the created stream.  |device_id| is the id of the audio device opened by
24  // the created stream.
25  virtual void OnCreated(int component_id,
26                         const media::AudioParameters& params,
27                         const std::string& device_id) = 0;
28
29  // Called when an audio component is started, generally this is synonymous
30  // with "playing."
31  virtual void OnStarted(int component_id) = 0;
32
33  // Called when an audio component is stopped, generally this is synonymous
34  // with "paused."
35  virtual void OnStopped(int component_id) = 0;
36
37  // Called when an audio component is closed, generally this is synonymous
38  // with "deleted."
39  virtual void OnClosed(int component_id) = 0;
40
41  // Called when an audio component encounters an error.
42  virtual void OnError(int component_id) = 0;
43
44  // Called when an audio component changes volume.  |volume| is the new volume.
45  virtual void OnSetVolume(int component_id, double volume) = 0;
46};
47
48// AudioLogFactory dispenses AudioLog instances to owning classes for tracking
49// AudioComponent behavior.  All AudioComponents have the concept of an owning
50// class:
51//
52//    - AudioInputRendererHost for AudioInputController
53//    - AudioRendererHost for AudioOutputController
54//    - AudioOutputDispatcherImpl for AudioOutputStream
55//
56// Each of these owning classes may own multiple instances of each component, as
57// such each AudioLog supports logging for multiple instances.
58class AudioLogFactory {
59 public:
60  enum AudioComponent {
61    // Input controllers have a 1:1 mapping with streams, so there's no need to
62    // track both controllers and streams.
63    AUDIO_INPUT_CONTROLLER,
64    // Output controllers may or may not be backed by an active stream, so we
65    // need to track both controllers and streams.
66    AUDIO_OUTPUT_CONTROLLER,
67    AUDIO_OUTPUT_STREAM,
68    AUDIO_COMPONENT_MAX
69  };
70
71  // Create a new AudioLog object for tracking the behavior for one or more
72  // instances of the given component.  Each instance of an "owning" class must
73  // create its own AudioLog.
74  virtual scoped_ptr<AudioLog> CreateAudioLog(AudioComponent component) = 0;
75
76 protected:
77  virtual ~AudioLogFactory() {}
78};
79
80}  // namespace media
81
82#endif  // MEDIA_AUDIO_AUDIO_LOGGING_H_
83