summaryrefslogtreecommitdiffstats
path: root/dom/media/webaudio/AudioNode.cpp
blob: f5c56d0da663ea1773e534a6886fb6e985e2c5b1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "AudioNode.h"
#include "mozilla/ErrorResult.h"
#include "AudioNodeTrack.h"
#include "AudioNodeEngine.h"
#include "mozilla/dom/AudioParam.h"
#include "mozilla/Services.h"
#include "nsIObserverService.h"

namespace mozilla::dom {

static const uint32_t INVALID_PORT = 0xffffffff;
static uint32_t gId = 0;

NS_IMPL_CYCLE_COLLECTION_CLASS(AudioNode)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(AudioNode, DOMEventTargetHelper)
  tmp->DisconnectFromGraph();
  if (tmp->mContext) {
    tmp->mContext->UnregisterNode(tmp);
  }
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mContext)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mParams)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOutputNodes)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOutputParams)
  NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(AudioNode,
                                                  DOMEventTargetHelper)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mContext)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParams)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOutputNodes)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOutputParams)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_ADDREF_INHERITED(AudioNode, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(AudioNode, DOMEventTargetHelper)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AudioNode)
  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

AudioNode::AudioNode(AudioContext* aContext, uint32_t aChannelCount,
                     ChannelCountMode aChannelCountMode,
                     ChannelInterpretation aChannelInterpretation)
    : DOMEventTargetHelper(aContext->GetParentObject()),
      mContext(aContext),
      mChannelCount(aChannelCount),
      mChannelCountMode(aChannelCountMode),
      mChannelInterpretation(aChannelInterpretation),
      mId(gId++),
      mPassThrough(false) {
  MOZ_ASSERT(aContext);
  aContext->RegisterNode(this);
}

AudioNode::~AudioNode() {
  MOZ_ASSERT(mInputNodes.IsEmpty());
  MOZ_ASSERT(mOutputNodes.IsEmpty());
  MOZ_ASSERT(mOutputParams.IsEmpty());
  MOZ_ASSERT(!mTrack,
             "The webaudio-node-demise notification must have been sent");
  if (mContext) {
    mContext->UnregisterNode(this);
  }
}

void AudioNode::Initialize(const AudioNodeOptions& aOptions, ErrorResult& aRv) {
  if (aOptions.mChannelCount.WasPassed()) {
    SetChannelCount(aOptions.mChannelCount.Value(), aRv);
    if (NS_WARN_IF(aRv.Failed())) {
      return;
    }
  }

  if (aOptions.mChannelCountMode.WasPassed()) {
    SetChannelCountModeValue(aOptions.mChannelCountMode.Value(), aRv);
    if (NS_WARN_IF(aRv.Failed())) {
      return;
    }
  }

  if (aOptions.mChannelInterpretation.WasPassed()) {
    SetChannelInterpretationValue(aOptions.mChannelInterpretation.Value(), aRv);
    if (NS_WARN_IF(aRv.Failed())) {
      return;
    }
  }
}

size_t AudioNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
  // Not owned:
  // - mContext
  // - mTrack
  size_t amount = 0;

  amount += mInputNodes.ShallowSizeOfExcludingThis(aMallocSizeOf);
  for (size_t i = 0; i < mInputNodes.Length(); i++) {
    amount += mInputNodes[i].SizeOfExcludingThis(aMallocSizeOf);
  }

  // Just measure the array. The entire audio node graph is measured via the
  // MediaTrackGraph's tracks, so we don't want to double-count the elements.
  amount += mOutputNodes.ShallowSizeOfExcludingThis(aMallocSizeOf);

  amount += mOutputParams.ShallowSizeOfExcludingThis(aMallocSizeOf);
  for (size_t i = 0; i < mOutputParams.Length(); i++) {
    amount += mOutputParams[i]->SizeOfIncludingThis(aMallocSizeOf);
  }

  return amount;
}

size_t AudioNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}

template <class InputNode>
static size_t FindIndexOfNode(const nsTArray<InputNode>& aInputNodes,
                              const AudioNode* aNode) {
  for (size_t i = 0; i < aInputNodes.Length(); ++i) {
    if (aInputNodes[i].mInputNode == aNode) {
      return i;
    }
  }
  return nsTArray<InputNode>::NoIndex;
}

template <class InputNode>
static size_t FindIndexOfNodeWithPorts(const nsTArray<InputNode>& aInputNodes,
                                       const AudioNode* aNode,
                                       uint32_t aInputPort,
                                       uint32_t aOutputPort) {
  for (size_t i = 0; i < aInputNodes.Length(); ++i) {
    if (aInputNodes[i].mInputNode == aNode &&
        aInputNodes[i].mInputPort == aInputPort &&
        aInputNodes[i].mOutputPort == aOutputPort) {
      return i;
    }
  }
  return nsTArray<InputNode>::NoIndex;
}

void AudioNode::DisconnectFromGraph() {
  MOZ_ASSERT(mRefCnt.get() > mInputNodes.Length(),
             "Caller should be holding a reference");

  // The idea here is that we remove connections one by one, and at each step
  // the graph is in a valid state.

  // Disconnect inputs. We don't need them anymore.
  while (!mInputNodes.IsEmpty()) {
    InputNode inputNode = mInputNodes.PopLastElement();
    inputNode.mInputNode->mOutputNodes.RemoveElement(this);
  }

  while (!mOutputNodes.IsEmpty()) {
    RefPtr<AudioNode> output = mOutputNodes.PopLastElement();
    size_t inputIndex = FindIndexOfNode(output->mInputNodes, this);
    // It doesn't matter which one we remove, since we're going to remove all
    // entries for this node anyway.
    output->mInputNodes.RemoveElementAt(inputIndex);
    // This effects of this connection will remain.
    output->NotifyHasPhantomInput();
  }

  while (!mOutputParams.IsEmpty()) {
    RefPtr<AudioParam> output = mOutputParams.PopLastElement();
    size_t inputIndex = FindIndexOfNode(output->InputNodes(), this);
    // It doesn't matter which one we remove, since we're going to remove all
    // entries for this node anyway.
    output->RemoveInputNode(inputIndex);
  }

  DestroyMediaTrack();
}

AudioNode* AudioNode::Connect(AudioNode& aDestination, uint32_t aOutput,
                              uint32_t aInput, ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return nullptr;
  }

  if (aInput >= aDestination.NumberOfInputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Input index %u is out of bounds", aInput));
    return nullptr;
  }

  if (Context() != aDestination.Context()) {
    aRv.ThrowInvalidAccessError(
        "Can't connect nodes from different AudioContexts");
    return nullptr;
  }

  if (FindIndexOfNodeWithPorts(aDestination.mInputNodes, this, aInput,
                               aOutput) !=
      nsTArray<AudioNode::InputNode>::NoIndex) {
    // connection already exists.
    return &aDestination;
  }

  WEB_AUDIO_API_LOG("%f: %s %u Connect() to %s %u", Context()->CurrentTime(),
                    NodeType(), Id(), aDestination.NodeType(),
                    aDestination.Id());

  // The MediaTrackGraph will handle cycle detection. We don't need to do it
  // here.

  mOutputNodes.AppendElement(&aDestination);
  InputNode* input = aDestination.mInputNodes.AppendElement();
  input->mInputNode = this;
  input->mInputPort = aInput;
  input->mOutputPort = aOutput;
  AudioNodeTrack* destinationTrack = aDestination.mTrack;
  if (mTrack && destinationTrack) {
    // Connect tracks in the MediaTrackGraph
    MOZ_ASSERT(aInput <= UINT16_MAX, "Unexpected large input port number");
    MOZ_ASSERT(aOutput <= UINT16_MAX, "Unexpected large output port number");
    input->mTrackPort = destinationTrack->AllocateInputPort(
        mTrack, static_cast<uint16_t>(aInput), static_cast<uint16_t>(aOutput));
  }
  aDestination.NotifyInputsChanged();

  return &aDestination;
}

void AudioNode::Connect(AudioParam& aDestination, uint32_t aOutput,
                        ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return;
  }

  if (Context() != aDestination.GetParentObject()) {
    aRv.ThrowInvalidAccessError(
        "Can't connect a node to an AudioParam from a different AudioContext");
    return;
  }

  if (FindIndexOfNodeWithPorts(aDestination.InputNodes(), this, INVALID_PORT,
                               aOutput) !=
      nsTArray<AudioNode::InputNode>::NoIndex) {
    // connection already exists.
    return;
  }

  mOutputParams.AppendElement(&aDestination);
  InputNode* input = aDestination.AppendInputNode();
  input->mInputNode = this;
  input->mInputPort = INVALID_PORT;
  input->mOutputPort = aOutput;

  mozilla::MediaTrack* track = aDestination.Track();
  MOZ_ASSERT(track->AsProcessedTrack());
  ProcessedMediaTrack* ps = static_cast<ProcessedMediaTrack*>(track);
  if (mTrack) {
    // Setup our track as an input to the AudioParam's track
    MOZ_ASSERT(aOutput <= UINT16_MAX, "Unexpected large output port number");
    input->mTrackPort =
        ps->AllocateInputPort(mTrack, 0, static_cast<uint16_t>(aOutput));
  }
}

void AudioNode::SendDoubleParameterToTrack(uint32_t aIndex, double aValue) {
  MOZ_ASSERT(mTrack, "How come we don't have a track here?");
  mTrack->SetDoubleParameter(aIndex, aValue);
}

void AudioNode::SendInt32ParameterToTrack(uint32_t aIndex, int32_t aValue) {
  MOZ_ASSERT(mTrack, "How come we don't have a track here?");
  mTrack->SetInt32Parameter(aIndex, aValue);
}

void AudioNode::SendChannelMixingParametersToTrack() {
  if (mTrack) {
    mTrack->SetChannelMixingParameters(mChannelCount, mChannelCountMode,
                                       mChannelInterpretation);
  }
}

template <>
bool AudioNode::DisconnectFromOutputIfConnected<AudioNode>(
    uint32_t aOutputNodeIndex, uint32_t aInputIndex) {
  WEB_AUDIO_API_LOG("%f: %s %u Disconnect()", Context()->CurrentTime(),
                    NodeType(), Id());

  AudioNode* destination = mOutputNodes[aOutputNodeIndex];

  MOZ_ASSERT(aOutputNodeIndex < mOutputNodes.Length());
  MOZ_ASSERT(aInputIndex < destination->InputNodes().Length());

  // An upstream node may be starting to play on the graph thread, and the
  // engine for a downstream node may be sending a PlayingRefChangeHandler
  // ADDREF message to this (main) thread.  Wait for a round trip before
  // releasing nodes, to give engines receiving sound now time to keep their
  // nodes alive.
  class RunnableRelease final : public Runnable {
   public:
    explicit RunnableRelease(already_AddRefed<AudioNode> aNode)
        : mozilla::Runnable("RunnableRelease"), mNode(aNode) {}

    NS_IMETHOD Run() override {
      mNode = nullptr;
      return NS_OK;
    }

   private:
    RefPtr<AudioNode> mNode;
  };

  InputNode& input = destination->mInputNodes[aInputIndex];
  if (input.mInputNode != this) {
    return false;
  }

  // Remove one instance of 'dest' from mOutputNodes. There could be
  // others, and it's not correct to remove them all since some of them
  // could be for different output ports.
  RefPtr<AudioNode> output = std::move(mOutputNodes[aOutputNodeIndex]);
  mOutputNodes.RemoveElementAt(aOutputNodeIndex);
  // Destroying the InputNode here sends a message to the graph thread
  // to disconnect the tracks, which should be sent before the
  // RunAfterPendingUpdates() call below.
  destination->mInputNodes.RemoveElementAt(aInputIndex);
  output->NotifyInputsChanged();
  if (mTrack) {
    nsCOMPtr<nsIRunnable> runnable = new RunnableRelease(output.forget());
    mTrack->RunAfterPendingUpdates(runnable.forget());
  }
  return true;
}

template <>
bool AudioNode::DisconnectFromOutputIfConnected<AudioParam>(
    uint32_t aOutputParamIndex, uint32_t aInputIndex) {
  MOZ_ASSERT(aOutputParamIndex < mOutputParams.Length());

  AudioParam* destination = mOutputParams[aOutputParamIndex];

  MOZ_ASSERT(aInputIndex < destination->InputNodes().Length());

  const InputNode& input = destination->InputNodes()[aInputIndex];
  if (input.mInputNode != this) {
    return false;
  }
  destination->RemoveInputNode(aInputIndex);
  // Remove one instance of 'dest' from mOutputParams. There could be
  // others, and it's not correct to remove them all since some of them
  // could be for different output ports.
  mOutputParams.RemoveElementAt(aOutputParamIndex);
  return true;
}

template <>
const nsTArray<AudioNode::InputNode>&
AudioNode::InputsForDestination<AudioNode>(uint32_t aOutputNodeIndex) const {
  return mOutputNodes[aOutputNodeIndex]->InputNodes();
}

template <>
const nsTArray<AudioNode::InputNode>&
AudioNode::InputsForDestination<AudioParam>(uint32_t aOutputNodeIndex) const {
  return mOutputParams[aOutputNodeIndex]->InputNodes();
}

template <typename DestinationType, typename Predicate>
bool AudioNode::DisconnectMatchingDestinationInputs(uint32_t aDestinationIndex,
                                                    Predicate aPredicate) {
  bool wasConnected = false;
  uint32_t inputCount =
      InputsForDestination<DestinationType>(aDestinationIndex).Length();

  for (int32_t inputIndex = inputCount - 1; inputIndex >= 0; --inputIndex) {
    const InputNode& input =
        InputsForDestination<DestinationType>(aDestinationIndex)[inputIndex];
    if (aPredicate(input)) {
      if (DisconnectFromOutputIfConnected<DestinationType>(aDestinationIndex,
                                                           inputIndex)) {
        wasConnected = true;
        break;
      }
    }
  }
  return wasConnected;
}

void AudioNode::Disconnect(ErrorResult& aRv) {
  for (int32_t outputIndex = mOutputNodes.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    DisconnectMatchingDestinationInputs<AudioNode>(
        outputIndex, [](const InputNode&) { return true; });
  }

  for (int32_t outputIndex = mOutputParams.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    DisconnectMatchingDestinationInputs<AudioParam>(
        outputIndex, [](const InputNode&) { return true; });
  }
}

void AudioNode::Disconnect(uint32_t aOutput, ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return;
  }

  for (int32_t outputIndex = mOutputNodes.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    DisconnectMatchingDestinationInputs<AudioNode>(
        outputIndex, [aOutput](const InputNode& aInputNode) {
          return aInputNode.mOutputPort == aOutput;
        });
  }

  for (int32_t outputIndex = mOutputParams.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    DisconnectMatchingDestinationInputs<AudioParam>(
        outputIndex, [aOutput](const InputNode& aInputNode) {
          return aInputNode.mOutputPort == aOutput;
        });
  }
}

void AudioNode::Disconnect(AudioNode& aDestination, ErrorResult& aRv) {
  bool wasConnected = false;

  for (int32_t outputIndex = mOutputNodes.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    if (mOutputNodes[outputIndex] != &aDestination) {
      continue;
    }
    wasConnected |= DisconnectMatchingDestinationInputs<AudioNode>(
        outputIndex, [](const InputNode&) { return true; });
  }

  if (!wasConnected) {
    aRv.ThrowInvalidAccessError(
        "Trying to disconnect from a node we're not connected to");
    return;
  }
}

void AudioNode::Disconnect(AudioNode& aDestination, uint32_t aOutput,
                           ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return;
  }

  bool wasConnected = false;

  for (int32_t outputIndex = mOutputNodes.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    if (mOutputNodes[outputIndex] != &aDestination) {
      continue;
    }
    wasConnected |= DisconnectMatchingDestinationInputs<AudioNode>(
        outputIndex, [aOutput](const InputNode& aInputNode) {
          return aInputNode.mOutputPort == aOutput;
        });
  }

  if (!wasConnected) {
    aRv.ThrowInvalidAccessError(
        "Trying to disconnect from a node we're not connected to");
    return;
  }
}

void AudioNode::Disconnect(AudioNode& aDestination, uint32_t aOutput,
                           uint32_t aInput, ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return;
  }

  if (aInput >= aDestination.NumberOfInputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Input index %u is out of bounds", aInput));
    return;
  }

  bool wasConnected = false;

  for (int32_t outputIndex = mOutputNodes.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    if (mOutputNodes[outputIndex] != &aDestination) {
      continue;
    }
    wasConnected |= DisconnectMatchingDestinationInputs<AudioNode>(
        outputIndex, [aOutput, aInput](const InputNode& aInputNode) {
          return aInputNode.mOutputPort == aOutput &&
                 aInputNode.mInputPort == aInput;
        });
  }

  if (!wasConnected) {
    aRv.ThrowInvalidAccessError(
        "Trying to disconnect from a node we're not connected to");
    return;
  }
}

void AudioNode::Disconnect(AudioParam& aDestination, ErrorResult& aRv) {
  bool wasConnected = false;

  for (int32_t outputIndex = mOutputParams.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    if (mOutputParams[outputIndex] != &aDestination) {
      continue;
    }
    wasConnected |= DisconnectMatchingDestinationInputs<AudioParam>(
        outputIndex, [](const InputNode&) { return true; });
  }

  if (!wasConnected) {
    aRv.ThrowInvalidAccessError(
        "Trying to disconnect from an AudioParam we're not connected to");
    return;
  }
}

void AudioNode::Disconnect(AudioParam& aDestination, uint32_t aOutput,
                           ErrorResult& aRv) {
  if (aOutput >= NumberOfOutputs()) {
    aRv.ThrowIndexSizeError(
        nsPrintfCString("Output index %u is out of bounds", aOutput));
    return;
  }

  bool wasConnected = false;

  for (int32_t outputIndex = mOutputParams.Length() - 1; outputIndex >= 0;
       --outputIndex) {
    if (mOutputParams[outputIndex] != &aDestination) {
      continue;
    }
    wasConnected |= DisconnectMatchingDestinationInputs<AudioParam>(
        outputIndex, [aOutput](const InputNode& aInputNode) {
          return aInputNode.mOutputPort == aOutput;
        });
  }

  if (!wasConnected) {
    aRv.ThrowInvalidAccessError(
        "Trying to disconnect from an AudioParam we're not connected to");
    return;
  }
}

void AudioNode::DestroyMediaTrack() {
  if (mTrack) {
    // Remove the node pointer on the engine.
    AudioNodeTrack* ns = mTrack;
    MOZ_ASSERT(ns, "How come we don't have a track here?");
    MOZ_ASSERT(ns->Engine()->NodeMainThread() == this,
               "Invalid node reference");
    ns->Engine()->ClearNode();

    mTrack->Destroy();
    mTrack = nullptr;

    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
    if (obs) {
      nsAutoString id;
      id.AppendPrintf("%u", mId);
      obs->NotifyObservers(nullptr, "webaudio-node-demise", id.get());
    }
  }
}

void AudioNode::RemoveOutputParam(AudioParam* aParam) {
  mOutputParams.RemoveElement(aParam);
}

bool AudioNode::PassThrough() const {
  MOZ_ASSERT(NumberOfInputs() <= 1 && NumberOfOutputs() == 1);
  return mPassThrough;
}

void AudioNode::SetPassThrough(bool aPassThrough) {
  MOZ_ASSERT(NumberOfInputs() <= 1 && NumberOfOutputs() == 1);
  mPassThrough = aPassThrough;
  if (mTrack) {
    mTrack->SetPassThrough(mPassThrough);
  }
}

AudioParam* AudioNode::CreateAudioParam(uint32_t aIndex, const nsAString& aName,
                                        float aDefaultValue, float aMinValue,
                                        float aMaxValue) {
  return *mParams.AppendElement(
      new AudioParam(this, aIndex, aName, aDefaultValue, aMinValue, aMaxValue));
}

}  // namespace mozilla::dom