1 files changed, 223 insertions, 0 deletions
diff --git a/dom/media/webaudio/DelayNode.cpp b/dom/media/webaudio/DelayNode.cpp
new file mode 100644
index 0000000000..3fb6819e41
--- /dev/null
+++ b/dom/media/webaudio/DelayNode.cpp
@@ -0,0 +1,223 @@
+/* -*- 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 "DelayNode.h"
+#include "mozilla/dom/DelayNodeBinding.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeTrack.h"
+#include "AudioDestinationNode.h"
+#include "WebAudioUtils.h"
+#include "DelayBuffer.h"
+#include "PlayingRefChangeHandler.h"
+#include "Tracing.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(DelayNode, AudioNode, mDelay)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DelayNode)
+NS_INTERFACE_MAP_END_INHERITING(AudioNode)
+
+NS_IMPL_ADDREF_INHERITED(DelayNode, AudioNode)
+NS_IMPL_RELEASE_INHERITED(DelayNode, AudioNode)
+
+class DelayNodeEngine final : public AudioNodeEngine {
+  typedef PlayingRefChangeHandler PlayingRefChanged;
+
+ public:
+  DelayNodeEngine(AudioNode* aNode, AudioDestinationNode* aDestination,
+                  float aMaxDelayTicks)
+      : AudioNodeEngine(aNode),
+        mDestination(aDestination->Track())
+        // Keep the default value in sync with the default value in
+        // DelayNode::DelayNode.
+        ,
+        mDelay(0.f)
+        // Use a smoothing range of 20ms
+        ,
+        mBuffer(
+            std::max(aMaxDelayTicks, static_cast<float>(WEBAUDIO_BLOCK_SIZE))),
+        mMaxDelay(aMaxDelayTicks),
+        mHaveProducedBeforeInput(false),
+        mLeftOverData(INT32_MIN) {}
+
+  DelayNodeEngine* AsDelayNodeEngine() override { return this; }
+
+  enum Parameters {
+    DELAY,
+  };
+  void RecvTimelineEvent(uint32_t aIndex, AudioTimelineEvent& aEvent) override {
+    MOZ_ASSERT(mDestination);
+    WebAudioUtils::ConvertAudioTimelineEventToTicks(aEvent, mDestination);
+
+    switch (aIndex) {
+      case DELAY:
+        mDelay.InsertEvent<int64_t>(aEvent);
+        break;
+      default:
+        NS_ERROR("Bad DelayNodeEngine TimelineParameter");
+    }
+  }
+
+  void ProcessBlock(AudioNodeTrack* aTrack, GraphTime aFrom,
+                    const AudioBlock& aInput, AudioBlock* aOutput,
+                    bool* aFinished) override {
+    MOZ_ASSERT(aTrack->mSampleRate == mDestination->mSampleRate);
+    TRACE("DelayNodeEngine::ProcessBlock");
+
+    if (!aInput.IsSilentOrSubnormal()) {
+      if (mLeftOverData <= 0) {
+        RefPtr<PlayingRefChanged> refchanged =
+            new PlayingRefChanged(aTrack, PlayingRefChanged::ADDREF);
+        aTrack->Graph()->DispatchToMainThreadStableState(refchanged.forget());
+      }
+      mLeftOverData = mBuffer.MaxDelayTicks();
+    } else if (mLeftOverData > 0) {
+      mLeftOverData -= WEBAUDIO_BLOCK_SIZE;
+    } else {
+      if (mLeftOverData != INT32_MIN) {
+        mLeftOverData = INT32_MIN;
+        aTrack->ScheduleCheckForInactive();
+
+        // Delete our buffered data now we no longer need it
+        mBuffer.Reset();
+
+        RefPtr<PlayingRefChanged> refchanged =
+            new PlayingRefChanged(aTrack, PlayingRefChanged::RELEASE);
+        aTrack->Graph()->DispatchToMainThreadStableState(refchanged.forget());
+      }
+      aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
+      return;
+    }
+
+    mBuffer.Write(aInput);
+
+    // Skip output update if mLastChunks has already been set by
+    // ProduceBlockBeforeInput() when in a cycle.
+    if (!mHaveProducedBeforeInput) {
+      UpdateOutputBlock(aTrack, aFrom, aOutput, 0.0);
+    }
+    mHaveProducedBeforeInput = false;
+    mBuffer.NextBlock();
+  }
+
+  void UpdateOutputBlock(AudioNodeTrack* aTrack, GraphTime aFrom,
+                         AudioBlock* aOutput, float minDelay) {
+    float maxDelay = mMaxDelay;
+    float sampleRate = aTrack->mSampleRate;
+    ChannelInterpretation channelInterpretation =
+        aTrack->GetChannelInterpretation();
+    if (mDelay.HasSimpleValue()) {
+      // If this DelayNode is in a cycle, make sure the delay value is at least
+      // one block, even if that is greater than maxDelay.
+      float delayFrames = mDelay.GetValue() * sampleRate;
+      float delayFramesClamped =
+          std::max(minDelay, std::min(delayFrames, maxDelay));
+      mBuffer.Read(delayFramesClamped, aOutput, channelInterpretation);
+    } else {
+      // Compute the delay values for the duration of the input AudioChunk
+      // If this DelayNode is in a cycle, make sure the delay value is at least
+      // one block.
+      TrackTime tick = mDestination->GraphTimeToTrackTime(aFrom);
+      float values[WEBAUDIO_BLOCK_SIZE];
+      mDelay.GetValuesAtTime(tick, values, WEBAUDIO_BLOCK_SIZE);
+
+      float computedDelay[WEBAUDIO_BLOCK_SIZE];
+      for (size_t counter = 0; counter < WEBAUDIO_BLOCK_SIZE; ++counter) {
+        float delayAtTick = values[counter] * sampleRate;
+        float delayAtTickClamped =
+            std::max(minDelay, std::min(delayAtTick, maxDelay));
+        computedDelay[counter] = delayAtTickClamped;
+      }
+      mBuffer.Read(computedDelay, aOutput, channelInterpretation);
+    }
+  }
+
+  void ProduceBlockBeforeInput(AudioNodeTrack* aTrack, GraphTime aFrom,
+                               AudioBlock* aOutput) override {
+    if (mLeftOverData <= 0) {
+      aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
+    } else {
+      UpdateOutputBlock(aTrack, aFrom, aOutput, WEBAUDIO_BLOCK_SIZE);
+    }
+    mHaveProducedBeforeInput = true;
+  }
+
+  bool IsActive() const override { return mLeftOverData != INT32_MIN; }
+
+  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override {
+    size_t amount = AudioNodeEngine::SizeOfExcludingThis(aMallocSizeOf);
+    // Not owned:
+    // - mDestination - probably not owned
+    // - mDelay - shares ref with AudioNode, don't count
+    amount += mBuffer.SizeOfExcludingThis(aMallocSizeOf);
+    return amount;
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  RefPtr<AudioNodeTrack> mDestination;
+  AudioParamTimeline mDelay;
+  DelayBuffer mBuffer;
+  float mMaxDelay;
+  bool mHaveProducedBeforeInput;
+  // How much data we have in our buffer which needs to be flushed out when our
+  // inputs finish.
+  int32_t mLeftOverData;
+};
+
+DelayNode::DelayNode(AudioContext* aContext, double aMaxDelay)
+    : AudioNode(aContext, 2, ChannelCountMode::Max,
+                ChannelInterpretation::Speakers) {
+  mDelay = CreateAudioParam(DelayNodeEngine::DELAY, u"delayTime"_ns, 0.0f, 0.f,
+                            aMaxDelay);
+  DelayNodeEngine* engine = new DelayNodeEngine(
+      this, aContext->Destination(), aContext->SampleRate() * aMaxDelay);
+  mTrack = AudioNodeTrack::Create(
+      aContext, engine, AudioNodeTrack::NO_TRACK_FLAGS, aContext->Graph());
+}
+
+/* static */
+already_AddRefed<DelayNode> DelayNode::Create(AudioContext& aAudioContext,
+                                              const DelayOptions& aOptions,
+                                              ErrorResult& aRv) {
+  if (aOptions.mMaxDelayTime <= 0. || aOptions.mMaxDelayTime >= 180.) {
+    aRv.ThrowNotSupportedError(
+        nsPrintfCString("\"maxDelayTime\" (%g) is not in the range (0,180)",
+                        aOptions.mMaxDelayTime));
+    return nullptr;
+  }
+
+  RefPtr<DelayNode> audioNode =
+      new DelayNode(&aAudioContext, aOptions.mMaxDelayTime);
+
+  audioNode->Initialize(aOptions, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  audioNode->DelayTime()->SetInitialValue(aOptions.mDelayTime);
+  return audioNode.forget();
+}
+
+size_t DelayNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
+  amount += mDelay->SizeOfIncludingThis(aMallocSizeOf);
+  return amount;
+}
+
+size_t DelayNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+JSObject* DelayNode::WrapObject(JSContext* aCx,
+                                JS::Handle<JSObject*> aGivenProto) {
+  return DelayNode_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom