content/browser/speech/speech_recognition_manager_impl.cc

   1 // Copyright (c) 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 #include "content/browser/speech/speech_recognition_manager_impl.h"
   6
   7 #include "base/bind.h"
   8 #include "content/browser/browser_main_loop.h"
   9 #include "content/browser/renderer_host/media/media_stream_manager.h"
  10 #include "content/browser/renderer_host/media/media_stream_ui_proxy.h"
  11 #include "content/browser/speech/google_one_shot_remote_engine.h"
  12 #include "content/browser/speech/google_streaming_remote_engine.h"
  13 #include "content/browser/speech/speech_recognition_engine.h"
  14 #include "content/browser/speech/speech_recognizer_impl.h"
  15 #include "content/public/browser/browser_thread.h"
  16 #include "content/public/browser/content_browser_client.h"
  17 #include "content/public/browser/resource_context.h"
  18 #include "content/public/browser/speech_recognition_event_listener.h"
  19 #include "content/public/browser/speech_recognition_manager_delegate.h"
  20 #include "content/public/browser/speech_recognition_session_config.h"
  21 #include "content/public/browser/speech_recognition_session_context.h"
  22 #include "content/public/common/speech_recognition_error.h"
  23 #include "content/public/common/speech_recognition_result.h"
  24 #include "media/audio/audio_manager.h"
  25 #include "media/audio/audio_manager_base.h"
  26
  27 #if defined(OS_ANDROID)
  28 #include "content/browser/speech/speech_recognizer_impl_android.h"
  29 #endif
  30
  31 using base::Callback;
  32
  33 namespace content {
  34
  35 SpeechRecognitionManager* SpeechRecognitionManager::manager_for_tests_;
  36
  37 namespace {
  38
  39 SpeechRecognitionManagerImpl* g_speech_recognition_manager_impl;
  40
  41 void ShowAudioInputSettingsOnFileThread(media::AudioManager* audio_manager) {
  42   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  43   audio_manager->ShowAudioInputSettings();
  44 }
  45
  46 }  // namespace
  47
  48 SpeechRecognitionManager* SpeechRecognitionManager::GetInstance() {
  49   if (manager_for_tests_)
  50     return manager_for_tests_;
  51   return SpeechRecognitionManagerImpl::GetInstance();
  52 }
  53
  54 void SpeechRecognitionManager::SetManagerForTesting(
  55     SpeechRecognitionManager* manager) {
  56   manager_for_tests_ = manager;
  57 }
  58
  59 SpeechRecognitionManagerImpl* SpeechRecognitionManagerImpl::GetInstance() {
  60   return g_speech_recognition_manager_impl;
  61 }
  62
  63 SpeechRecognitionManagerImpl::SpeechRecognitionManagerImpl(
  64       media::AudioManager* audio_manager,
  65       MediaStreamManager* media_stream_manager)
  66     : audio_manager_(audio_manager),
  67       media_stream_manager_(media_stream_manager),
  68       primary_session_id_(kSessionIDInvalid),
  69       last_session_id_(kSessionIDInvalid),
  70       is_dispatching_event_(false),
  71       delegate_(GetContentClient()->browser()->
  72                     GetSpeechRecognitionManagerDelegate()),
  73       weak_factory_(this) {
  74   DCHECK(!g_speech_recognition_manager_impl);
  75   g_speech_recognition_manager_impl = this;
  76 }
  77
  78 SpeechRecognitionManagerImpl::~SpeechRecognitionManagerImpl() {
  79   DCHECK(g_speech_recognition_manager_impl);
  80   g_speech_recognition_manager_impl = NULL;
  81
  82   for (SessionsTable::iterator it = sessions_.begin(); it != sessions_.end();
  83        ++it) {
  84     // MediaStreamUIProxy must be deleted on the IO thread.
  85     BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE,
  86                               it->second->ui.release());
  87     delete it->second;
  88   }
  89   sessions_.clear();
  90 }
  91
  92 int SpeechRecognitionManagerImpl::CreateSession(
  93     const SpeechRecognitionSessionConfig& config) {
  94   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  95
  96   const int session_id = GetNextSessionID();
  97   DCHECK(!SessionExists(session_id));
  98   // Set-up the new session.
  99   Session* session = new Session();
 100   sessions_[session_id] = session;
 101   session->id = session_id;
 102   session->config = config;
 103   session->context = config.initial_context;
 104
 105   std::string hardware_info;
 106   bool can_report_metrics = false;
 107   if (delegate_)
 108     delegate_->GetDiagnosticInformation(&can_report_metrics, &hardware_info);
 109
 110   // The legacy api cannot use continuous mode.
 111   DCHECK(!config.is_legacy_api || !config.continuous);
 112
 113 #if !defined(OS_ANDROID)
 114   // A SpeechRecognitionEngine (and corresponding Config) is required only
 115   // when using SpeechRecognizerImpl, which performs the audio capture and
 116   // endpointing in the browser. This is not the case of Android where, not
 117   // only the speech recognition, but also the audio capture and endpointing
 118   // activities performed outside of the browser (delegated via JNI to the
 119   // Android API implementation).
 120
 121   SpeechRecognitionEngineConfig remote_engine_config;
 122   remote_engine_config.language = config.language;
 123   remote_engine_config.grammars = config.grammars;
 124   remote_engine_config.audio_sample_rate =
 125       SpeechRecognizerImpl::kAudioSampleRate;
 126   remote_engine_config.audio_num_bits_per_sample =
 127       SpeechRecognizerImpl::kNumBitsPerAudioSample;
 128   remote_engine_config.filter_profanities = config.filter_profanities;
 129   remote_engine_config.continuous = config.continuous;
 130   remote_engine_config.interim_results = config.interim_results;
 131   remote_engine_config.max_hypotheses = config.max_hypotheses;
 132   remote_engine_config.hardware_info = hardware_info;
 133   remote_engine_config.origin_url =
 134       can_report_metrics ? config.origin_url : std::string();
 135
 136   SpeechRecognitionEngine* google_remote_engine;
 137   if (config.is_legacy_api) {
 138     google_remote_engine =
 139         new GoogleOneShotRemoteEngine(config.url_request_context_getter.get());
 140   } else {
 141     google_remote_engine = new GoogleStreamingRemoteEngine(
 142         config.url_request_context_getter.get());
 143   }
 144
 145   google_remote_engine->SetConfig(remote_engine_config);
 146
 147   session->recognizer = new SpeechRecognizerImpl(
 148       this,
 149       session_id,
 150       config.continuous,
 151       config.interim_results,
 152       google_remote_engine);
 153 #else
 154   session->recognizer = new SpeechRecognizerImplAndroid(this, session_id);
 155 #endif
 156   return session_id;
 157 }
 158
 159 void SpeechRecognitionManagerImpl::StartSession(int session_id) {
 160   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 161   if (!SessionExists(session_id))
 162     return;
 163
 164   // If there is another active session, abort that.
 165   if (primary_session_id_ != kSessionIDInvalid &&
 166       primary_session_id_ != session_id) {
 167     AbortSession(primary_session_id_);
 168   }
 169
 170   primary_session_id_ = session_id;
 171
 172   if (delegate_) {
 173     delegate_->CheckRecognitionIsAllowed(
 174         session_id,
 175         base::Bind(&SpeechRecognitionManagerImpl::RecognitionAllowedCallback,
 176                    weak_factory_.GetWeakPtr(),
 177                    session_id));
 178   }
 179 }
 180
 181 void SpeechRecognitionManagerImpl::RecognitionAllowedCallback(int session_id,
 182                                                               bool ask_user,
 183                                                               bool is_allowed) {
 184   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 185   if (!SessionExists(session_id))
 186     return;
 187
 188   SessionsTable::iterator iter = sessions_.find(session_id);
 189   DCHECK(iter != sessions_.end());
 190   Session* session = iter->second;
 191
 192   if (session->abort_requested)
 193     return;
 194
 195   if (ask_user) {
 196     SpeechRecognitionSessionContext& context = session->context;
 197     context.label = media_stream_manager_->MakeMediaAccessRequest(
 198         context.render_process_id,
 199         context.render_view_id,
 200         context.request_id,
 201         StreamOptions(true, false),
 202         GURL(context.context_name),
 203         base::Bind(
 204             &SpeechRecognitionManagerImpl::MediaRequestPermissionCallback,
 205             weak_factory_.GetWeakPtr(), session_id));
 206     return;
 207   }
 208
 209   if (is_allowed) {
 210     base::MessageLoop::current()->PostTask(
 211         FROM_HERE,
 212         base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 213                    weak_factory_.GetWeakPtr(),
 214                    session_id,
 215                    EVENT_START));
 216   } else {
 217     OnRecognitionError(session_id, SpeechRecognitionError(
 218         SPEECH_RECOGNITION_ERROR_NOT_ALLOWED));
 219     base::MessageLoop::current()->PostTask(
 220         FROM_HERE,
 221         base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 222                    weak_factory_.GetWeakPtr(),
 223                    session_id,
 224                    EVENT_ABORT));
 225   }
 226 }
 227
 228 void SpeechRecognitionManagerImpl::MediaRequestPermissionCallback(
 229     int session_id,
 230     const MediaStreamDevices& devices,
 231     scoped_ptr<MediaStreamUIProxy> stream_ui) {
 232   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 233
 234   SessionsTable::iterator iter = sessions_.find(session_id);
 235   if (iter == sessions_.end())
 236     return;
 237
 238   bool is_allowed = !devices.empty();
 239   if (is_allowed) {
 240     // Copy the approved devices array to the context for UI indication.
 241     iter->second->context.devices = devices;
 242
 243     // Save the UI object.
 244     iter->second->ui = stream_ui.Pass();
 245   }
 246
 247   // Clear the label to indicate the request has been done.
 248   iter->second->context.label.clear();
 249
 250   // Notify the recognition about the request result.
 251   RecognitionAllowedCallback(iter->first, false, is_allowed);
 252 }
 253
 254 void SpeechRecognitionManagerImpl::AbortSession(int session_id) {
 255   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 256   if (!SessionExists(session_id))
 257     return;
 258
 259   SessionsTable::iterator iter = sessions_.find(session_id);
 260   iter->second->ui.reset();
 261
 262   if (iter->second->abort_requested)
 263     return;
 264
 265   iter->second->abort_requested = true;
 266
 267   base::MessageLoop::current()->PostTask(
 268       FROM_HERE,
 269       base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 270                  weak_factory_.GetWeakPtr(),
 271                  session_id,
 272                  EVENT_ABORT));
 273 }
 274
 275 void SpeechRecognitionManagerImpl::StopAudioCaptureForSession(int session_id) {
 276   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 277   if (!SessionExists(session_id))
 278     return;
 279
 280   SessionsTable::iterator iter = sessions_.find(session_id);
 281   iter->second->ui.reset();
 282
 283   base::MessageLoop::current()->PostTask(
 284       FROM_HERE,
 285       base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 286                  weak_factory_.GetWeakPtr(),
 287                  session_id,
 288                  EVENT_STOP_CAPTURE));
 289 }
 290
 291 // Here begins the SpeechRecognitionEventListener interface implementation,
 292 // which will simply relay the events to the proper listener registered for the
 293 // particular session (most likely InputTagSpeechDispatcherHost) and to the
 294 // catch-all listener provided by the delegate (if any).
 295
 296 void SpeechRecognitionManagerImpl::OnRecognitionStart(int session_id) {
 297   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 298   if (!SessionExists(session_id))
 299     return;
 300
 301   SessionsTable::iterator iter = sessions_.find(session_id);
 302   if (iter->second->ui) {
 303     // Notify the UI that the devices are being used.
 304     iter->second->ui->OnStarted(base::Closure());
 305   }
 306
 307   DCHECK_EQ(primary_session_id_, session_id);
 308   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 309     delegate_listener->OnRecognitionStart(session_id);
 310   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 311     listener->OnRecognitionStart(session_id);
 312 }
 313
 314 void SpeechRecognitionManagerImpl::OnAudioStart(int session_id) {
 315   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 316   if (!SessionExists(session_id))
 317     return;
 318
 319   DCHECK_EQ(primary_session_id_, session_id);
 320   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 321     delegate_listener->OnAudioStart(session_id);
 322   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 323     listener->OnAudioStart(session_id);
 324 }
 325
 326 void SpeechRecognitionManagerImpl::OnEnvironmentEstimationComplete(
 327     int session_id) {
 328   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 329   if (!SessionExists(session_id))
 330     return;
 331
 332   DCHECK_EQ(primary_session_id_, session_id);
 333   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 334     delegate_listener->OnEnvironmentEstimationComplete(session_id);
 335   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 336     listener->OnEnvironmentEstimationComplete(session_id);
 337 }
 338
 339 void SpeechRecognitionManagerImpl::OnSoundStart(int session_id) {
 340   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 341   if (!SessionExists(session_id))
 342     return;
 343
 344   DCHECK_EQ(primary_session_id_, session_id);
 345   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 346     delegate_listener->OnSoundStart(session_id);
 347   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 348     listener->OnSoundStart(session_id);
 349 }
 350
 351 void SpeechRecognitionManagerImpl::OnSoundEnd(int session_id) {
 352   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 353   if (!SessionExists(session_id))
 354     return;
 355
 356   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 357     delegate_listener->OnSoundEnd(session_id);
 358   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 359     listener->OnSoundEnd(session_id);
 360 }
 361
 362 void SpeechRecognitionManagerImpl::OnAudioEnd(int session_id) {
 363   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 364   if (!SessionExists(session_id))
 365     return;
 366
 367   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 368     delegate_listener->OnAudioEnd(session_id);
 369   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 370     listener->OnAudioEnd(session_id);
 371   base::MessageLoop::current()->PostTask(
 372       FROM_HERE,
 373       base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 374                  weak_factory_.GetWeakPtr(),
 375                  session_id,
 376                  EVENT_AUDIO_ENDED));
 377 }
 378
 379 void SpeechRecognitionManagerImpl::OnRecognitionResults(
 380     int session_id, const SpeechRecognitionResults& results) {
 381   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 382   if (!SessionExists(session_id))
 383     return;
 384
 385   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 386     delegate_listener->OnRecognitionResults(session_id, results);
 387   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 388     listener->OnRecognitionResults(session_id, results);
 389 }
 390
 391 void SpeechRecognitionManagerImpl::OnRecognitionError(
 392     int session_id, const SpeechRecognitionError& error) {
 393   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 394   if (!SessionExists(session_id))
 395     return;
 396
 397   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 398     delegate_listener->OnRecognitionError(session_id, error);
 399   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 400     listener->OnRecognitionError(session_id, error);
 401 }
 402
 403 void SpeechRecognitionManagerImpl::OnAudioLevelsChange(
 404     int session_id, float volume, float noise_volume) {
 405   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 406   if (!SessionExists(session_id))
 407     return;
 408
 409   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 410     delegate_listener->OnAudioLevelsChange(session_id, volume, noise_volume);
 411   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 412     listener->OnAudioLevelsChange(session_id, volume, noise_volume);
 413 }
 414
 415 void SpeechRecognitionManagerImpl::OnRecognitionEnd(int session_id) {
 416   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 417   if (!SessionExists(session_id))
 418     return;
 419
 420   if (SpeechRecognitionEventListener* delegate_listener = GetDelegateListener())
 421     delegate_listener->OnRecognitionEnd(session_id);
 422   if (SpeechRecognitionEventListener* listener = GetListener(session_id))
 423     listener->OnRecognitionEnd(session_id);
 424   base::MessageLoop::current()->PostTask(
 425       FROM_HERE,
 426       base::Bind(&SpeechRecognitionManagerImpl::DispatchEvent,
 427                  weak_factory_.GetWeakPtr(),
 428                  session_id,
 429                  EVENT_RECOGNITION_ENDED));
 430 }
 431
 432 int SpeechRecognitionManagerImpl::GetSession(
 433     int render_process_id, int render_view_id, int request_id) const {
 434   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 435   SessionsTable::const_iterator iter;
 436   for(iter = sessions_.begin(); iter != sessions_.end(); ++iter) {
 437     const int session_id = iter->first;
 438     const SpeechRecognitionSessionContext& context = iter->second->context;
 439     if (context.render_process_id == render_process_id &&
 440         context.render_view_id == render_view_id &&
 441         context.request_id == request_id) {
 442       return session_id;
 443     }
 444   }
 445   return kSessionIDInvalid;
 446 }
 447
 448 SpeechRecognitionSessionContext
 449 SpeechRecognitionManagerImpl::GetSessionContext(int session_id) const {
 450   return GetSession(session_id)->context;
 451 }
 452
 453 void SpeechRecognitionManagerImpl::AbortAllSessionsForListener(
 454     SpeechRecognitionEventListener* listener) {
 455   // This method gracefully destroys sessions for the listener. However, since
 456   // the listener itself is likely to be destroyed after this call, we avoid
 457   // dispatching further events to it, marking the |listener_is_active| flag.
 458   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 459   for (SessionsTable::iterator it = sessions_.begin(); it != sessions_.end();
 460        ++it) {
 461     Session* session = it->second;
 462     if (session->config.event_listener == listener) {
 463       AbortSession(session->id);
 464       session->listener_is_active = false;
 465     }
 466   }
 467 }
 468
 469 void SpeechRecognitionManagerImpl::AbortAllSessionsForRenderView(
 470     int render_process_id,
 471     int render_view_id) {
 472   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 473   for (SessionsTable::iterator it = sessions_.begin(); it != sessions_.end();
 474        ++it) {
 475     Session* session = it->second;
 476     if (session->context.render_process_id == render_process_id &&
 477         session->context.render_view_id == render_view_id) {
 478       AbortSession(session->id);
 479     }
 480   }
 481 }
 482
 483 // -----------------------  Core FSM implementation ---------------------------
 484 void SpeechRecognitionManagerImpl::DispatchEvent(int session_id,
 485                                                  FSMEvent event) {
 486   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 487
 488   // There are some corner cases in which the session might be deleted (due to
 489   // an EndRecognition event) between a request (e.g. Abort) and its dispatch.
 490   if (!SessionExists(session_id))
 491     return;
 492
 493   Session* session = GetSession(session_id);
 494   FSMState session_state = GetSessionState(session_id);
 495   DCHECK_LE(session_state, SESSION_STATE_MAX_VALUE);
 496   DCHECK_LE(event, EVENT_MAX_VALUE);
 497
 498   // Event dispatching must be sequential, otherwise it will break all the rules
 499   // and the assumptions of the finite state automata model.
 500   DCHECK(!is_dispatching_event_);
 501   is_dispatching_event_ = true;
 502   ExecuteTransitionAndGetNextState(session, session_state, event);
 503   is_dispatching_event_ = false;
 504 }
 505
 506 // This FSM handles the evolution of each session, from the viewpoint of the
 507 // interaction with the user (that may be either the browser end-user which
 508 // interacts with UI bubbles, or JS developer intracting with JS methods).
 509 // All the events received by the SpeechRecognizer instances (one for each
 510 // session) are always routed to the SpeechRecognitionEventListener(s)
 511 // regardless the choices taken in this FSM.
 512 void SpeechRecognitionManagerImpl::ExecuteTransitionAndGetNextState(
 513     Session* session, FSMState session_state, FSMEvent event) {
 514   // Note: since we're not tracking the state of the recognizer object, rather
 515   // we're directly retrieving it (through GetSessionState), we see its events
 516   // (that are AUDIO_ENDED and RECOGNITION_ENDED) after its state evolution
 517   // (e.g., when we receive the AUDIO_ENDED event, the recognizer has just
 518   // completed the transition from CAPTURING_AUDIO to WAITING_FOR_RESULT, thus
 519   // we perceive the AUDIO_ENDED event in WAITING_FOR_RESULT).
 520   // This makes the code below a bit tricky but avoids a lot of code for
 521   // tracking and reconstructing asynchronously the state of the recognizer.
 522   switch (session_state) {
 523     case SESSION_STATE_IDLE:
 524       switch (event) {
 525         case EVENT_START:
 526           return SessionStart(*session);
 527         case EVENT_ABORT:
 528           return SessionAbort(*session);
 529         case EVENT_RECOGNITION_ENDED:
 530           return SessionDelete(session);
 531         case EVENT_STOP_CAPTURE:
 532           return SessionStopAudioCapture(*session);
 533         case EVENT_AUDIO_ENDED:
 534           return;
 535       }
 536       break;
 537     case SESSION_STATE_CAPTURING_AUDIO:
 538       switch (event) {
 539         case EVENT_STOP_CAPTURE:
 540           return SessionStopAudioCapture(*session);
 541         case EVENT_ABORT:
 542           return SessionAbort(*session);
 543         case EVENT_START:
 544           return;
 545         case EVENT_AUDIO_ENDED:
 546         case EVENT_RECOGNITION_ENDED:
 547           return NotFeasible(*session, event);
 548       }
 549       break;
 550     case SESSION_STATE_WAITING_FOR_RESULT:
 551       switch (event) {
 552         case EVENT_ABORT:
 553           return SessionAbort(*session);
 554         case EVENT_AUDIO_ENDED:
 555           return ResetCapturingSessionId(*session);
 556         case EVENT_START:
 557         case EVENT_STOP_CAPTURE:
 558           return;
 559         case EVENT_RECOGNITION_ENDED:
 560           return NotFeasible(*session, event);
 561       }
 562       break;
 563   }
 564   return NotFeasible(*session, event);
 565 }
 566
 567 SpeechRecognitionManagerImpl::FSMState
 568 SpeechRecognitionManagerImpl::GetSessionState(int session_id) const {
 569   Session* session = GetSession(session_id);
 570   if (!session->recognizer.get() || !session->recognizer->IsActive())
 571     return SESSION_STATE_IDLE;
 572   if (session->recognizer->IsCapturingAudio())
 573     return SESSION_STATE_CAPTURING_AUDIO;
 574   return SESSION_STATE_WAITING_FOR_RESULT;
 575 }
 576
 577 // ----------- Contract for all the FSM evolution functions below -------------
 578 //  - Are guaranteed to be executed in the IO thread;
 579 //  - Are guaranteed to be not reentrant (themselves and each other);
 580
 581 void SpeechRecognitionManagerImpl::SessionStart(const Session& session) {
 582   DCHECK_EQ(primary_session_id_, session.id);
 583   const MediaStreamDevices& devices = session.context.devices;
 584   std::string device_id;
 585   if (devices.empty()) {
 586     // From the ask_user=false path, use the default device.
 587     // TODO(xians): Abort the session after we do not need to support this path
 588     // anymore.
 589     device_id = media::AudioManagerBase::kDefaultDeviceId;
 590   } else {
 591     // From the ask_user=true path, use the selected device.
 592     DCHECK_EQ(1u, devices.size());
 593     DCHECK_EQ(MEDIA_DEVICE_AUDIO_CAPTURE, devices.front().type);
 594     device_id = devices.front().id;
 595   }
 596
 597   session.recognizer->StartRecognition(device_id);
 598 }
 599
 600 void SpeechRecognitionManagerImpl::SessionAbort(const Session& session) {
 601   if (primary_session_id_ == session.id)
 602     primary_session_id_ = kSessionIDInvalid;
 603   DCHECK(session.recognizer.get());
 604   session.recognizer->AbortRecognition();
 605 }
 606
 607 void SpeechRecognitionManagerImpl::SessionStopAudioCapture(
 608     const Session& session) {
 609   DCHECK(session.recognizer.get());
 610   session.recognizer->StopAudioCapture();
 611 }
 612
 613 void SpeechRecognitionManagerImpl::ResetCapturingSessionId(
 614     const Session& session) {
 615   DCHECK_EQ(primary_session_id_, session.id);
 616   primary_session_id_ = kSessionIDInvalid;
 617 }
 618
 619 void SpeechRecognitionManagerImpl::SessionDelete(Session* session) {
 620   DCHECK(session->recognizer.get() == NULL || !session->recognizer->IsActive());
 621   if (primary_session_id_ == session->id)
 622     primary_session_id_ = kSessionIDInvalid;
 623   if (!session->context.label.empty())
 624     media_stream_manager_->CancelRequest(session->context.label);
 625   sessions_.erase(session->id);
 626   delete session;
 627 }
 628
 629 void SpeechRecognitionManagerImpl::NotFeasible(const Session& session,
 630                                                FSMEvent event) {
 631   NOTREACHED() << "Unfeasible event " << event
 632                << " in state " << GetSessionState(session.id)
 633                << " for session " << session.id;
 634 }
 635
 636 int SpeechRecognitionManagerImpl::GetNextSessionID() {
 637   ++last_session_id_;
 638   // Deal with wrapping of last_session_id_. (How civilized).
 639   if (last_session_id_ <= 0)
 640     last_session_id_ = 1;
 641   return last_session_id_;
 642 }
 643
 644 bool SpeechRecognitionManagerImpl::SessionExists(int session_id) const {
 645   return sessions_.find(session_id) != sessions_.end();
 646 }
 647
 648 SpeechRecognitionManagerImpl::Session*
 649 SpeechRecognitionManagerImpl::GetSession(int session_id) const {
 650   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 651   SessionsTable::const_iterator iter = sessions_.find(session_id);
 652   DCHECK(iter != sessions_.end());
 653   return iter->second;
 654 }
 655
 656 SpeechRecognitionEventListener* SpeechRecognitionManagerImpl::GetListener(
 657     int session_id) const {
 658   Session* session = GetSession(session_id);
 659   return session->listener_is_active ? session->config.event_listener : NULL;
 660 }
 661
 662 SpeechRecognitionEventListener*
 663 SpeechRecognitionManagerImpl::GetDelegateListener() const {
 664   return delegate_.get() ? delegate_->GetEventListener() : NULL;
 665 }
 666
 667 const SpeechRecognitionSessionConfig&
 668 SpeechRecognitionManagerImpl::GetSessionConfig(int session_id) const {
 669   return GetSession(session_id)->config;
 670 }
 671
 672 bool SpeechRecognitionManagerImpl::HasAudioInputDevices() {
 673   return audio_manager_->HasAudioInputDevices();
 674 }
 675
 676 base::string16 SpeechRecognitionManagerImpl::GetAudioInputDeviceModel() {
 677   return audio_manager_->GetAudioInputDeviceModel();
 678 }
 679
 680 void SpeechRecognitionManagerImpl::ShowAudioInputSettings() {
 681   // Since AudioManager::ShowAudioInputSettings can potentially launch external
 682   // processes, do that in the FILE thread to not block the calling threads.
 683   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
 684                           base::Bind(&ShowAudioInputSettingsOnFileThread,
 685                                      audio_manager_));
 686 }
 687
 688 SpeechRecognitionManagerImpl::Session::Session()
 689   : id(kSessionIDInvalid),
 690     abort_requested(false),
 691     listener_is_active(true) {
 692 }
 693
 694 SpeechRecognitionManagerImpl::Session::~Session() {
 695 }
 696
 697 }  // namespace content