audio_logging.h revision f2477e01787aa58f445919b809d89e252beef54f 
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.  |input_device_id| and |output_device_id| are the
24  // respective device ids for input and output.  Either one or both may be
25  // specified.
26  virtual void OnCreated(int component_id,
27                         const media::AudioParameters& params,
28                         const std::string& input_device_id,
29                         const std::string& output_device_id) = 0;
30
31  // Called when an audio component is started, generally this is synonymous
32  // with "playing."
33  virtual void OnStarted(int component_id) = 0;
34
35  // Called when an audio component is stopped, generally this is synonymous
36  // with "paused."
37  virtual void OnStopped(int component_id) = 0;
38
39  // Called when an audio component is closed, generally this is synonymous
40  // with "deleted."
41  virtual void OnClosed(int component_id) = 0;
42
43  // Called when an audio component encounters an error.
44  virtual void OnError(int component_id) = 0;
45
46  // Called when an audio component changes volume.  |volume| is the new volume.
47  virtual void OnSetVolume(int component_id, double volume) = 0;
48};
49
50// AudioLogFactory dispenses AudioLog instances to owning classes for tracking
51// AudioComponent behavior.  All AudioComponents have the concept of an owning
52// class:
53//
54//    - AudioInputRendererHost for AudioInputController
55//    - AudioRendererHost for AudioOutputController
56//    - AudioOutputDispatcherImpl for AudioOutputStream
57//
58// Each of these owning classes may own multiple instances of each component, as
59// such each AudioLog supports logging for multiple instances.
60class AudioLogFactory {
61 public:
62  enum AudioComponent {
63    // Input controllers have a 1:1 mapping with streams, so there's no need to
64    // track both controllers and streams.
65    AUDIO_INPUT_CONTROLLER,
66    // Output controllers may or may not be backed by an active stream, so we
67    // need to track both controllers and streams.
68    AUDIO_OUTPUT_CONTROLLER,
69    AUDIO_OUTPUT_STREAM,
70    AUDIO_COMPONENT_MAX
71  };
72
73  // Create a new AudioLog object for tracking the behavior for one or more
74  // instances of the given component.  Each instance of an "owning" class must
75  // create its own AudioLog.
76  virtual scoped_ptr<AudioLog> CreateAudioLog(AudioComponent component) = 0;
77
78 protected:
79  virtual ~AudioLogFactory() {}
80};
81
82}  // namespace media
83
84#endif  // MEDIA_AUDIO_AUDIO_LOGGING_H_
85