components/audio_modem/modem_impl.h

   1 // Copyright 2015 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 COMPONENTS_AUDIO_MODEM_MODEM_IMPL_H_
   6 #define COMPONENTS_AUDIO_MODEM_MODEM_IMPL_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback.h"
  12 #include "base/cancelable_callback.h"
  13 #include "base/containers/mru_cache.h"
  14 #include "base/files/file_path.h"
  15 #include "base/macros.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/memory/scoped_vector.h"
  18 #include "components/audio_modem/public/audio_modem_types.h"
  19 #include "components/audio_modem/public/modem.h"
  20 #include "media/base/audio_bus.h"
  21
  22 namespace base {
  23 class Time;
  24 }
  25
  26 namespace audio_modem {
  27
  28 class AudioPlayer;
  29 class AudioRecorder;
  30 class WhispernetClient;
  31
  32 // The ModemImpl class manages the playback and recording of tokens.
  33 // Clients should not necessary expect the modem to play or record continuously.
  34 // In the future, it may timeslice multiple tokens, or implement carrier sense.
  35 class ModemImpl final : public Modem {
  36  public:
  37   ModemImpl();
  38   ~ModemImpl() override;
  39
  40   // Modem overrides:
  41   void Initialize(WhispernetClient* client,
  42                   const TokensCallback& tokens_cb) override;
  43   void StartPlaying(AudioType type) override;
  44   void StopPlaying(AudioType type) override;
  45   void StartRecording(AudioType type) override;
  46   void StopRecording(AudioType type) override;
  47   void SetToken(AudioType type, const std::string& url_safe_token) override;
  48   const std::string GetToken(AudioType type) override;
  49   bool IsPlayingTokenHeard(AudioType type) override;
  50   void SetTokenLength(AudioType type, size_t token_length) override;
  51
  52   void set_player_for_testing(AudioType type, AudioPlayer* player) {
  53     player_[type] = player;
  54   }
  55   void set_recorder_for_testing(AudioRecorder* recorder) {
  56     recorder_ = recorder;
  57   }
  58
  59  private:
  60   using SamplesMap = base::MRUCache<std::string,
  61                                     scoped_refptr<media::AudioBusRefCounted>>;
  62
  63   // Receives the audio samples from encoding a token.
  64   void OnTokenEncoded(AudioType type,
  65                       const std::string& token,
  66                       const scoped_refptr<media::AudioBusRefCounted>& samples);
  67
  68   // Receives any tokens found by decoding audio samples.
  69   void OnTokensFound(const std::vector<AudioToken>& tokens);
  70
  71   // Update our currently playing token with the new token. Change the playing
  72   // samples if needed. Prerequisite: Samples corresponding to this token
  73   // should already be in the samples cache.
  74   void UpdateToken(AudioType type, const std::string& token);
  75
  76   void RestartPlaying(AudioType type);
  77
  78   void DecodeSamplesConnector(const std::string& samples);
  79
  80   void DumpToken(AudioType audio_type,
  81                  const std::string& token,
  82                  const media::AudioBus* samples);
  83
  84   WhispernetClient* client_;
  85
  86   // Callbacks to send tokens back to the client.
  87   TokensCallback tokens_cb_;
  88
  89   // This cancelable callback is passed to the recorder. The recorder's
  90   // destruction will happen on the audio thread, so it can outlive us.
  91   base::CancelableCallback<void(const std::string&)> decode_cancelable_cb_;
  92
  93   // We use the AudioType enum to index into all our data structures that work
  94   // on values for both audible and inaudible.
  95   static_assert(AUDIBLE == 0, "AudioType::AUDIBLE should be 0.");
  96   static_assert(INAUDIBLE == 1, "AudioType::INAUDIBLE should be 1.");
  97
  98   // Indexed using enum AudioType.
  99   bool player_enabled_[2];
 100   bool should_be_playing_[2];
 101   bool should_be_recording_[2];
 102
 103   // AudioPlayer and AudioRecorder objects are self-deleting. When we call
 104   // Finalize on them, they clean themselves up on the Audio thread.
 105   // Indexed using enum AudioType.
 106   AudioPlayer* player_[2];
 107   AudioRecorder* recorder_;
 108
 109   // Indexed using enum AudioType.
 110   std::string playing_token_[2];
 111   size_t token_length_[2];
 112   base::Time started_playing_[2];
 113   base::Time heard_own_token_[2];
 114
 115   // Cache that holds the encoded samples. After reaching its limit, the cache
 116   // expires the oldest samples first.
 117   // Indexed using enum AudioType.
 118   ScopedVector<SamplesMap> samples_caches_;
 119
 120   base::FilePath dump_tokens_dir_;
 121
 122   DISALLOW_COPY_AND_ASSIGN(ModemImpl);
 123 };
 124
 125 }  // namespace audio_modem
 126
 127 #endif  // COMPONENTS_AUDIO_MODEM_MODEM_IMPL_H_