1 files changed, 279 insertions, 0 deletions
diff --git a/dom/media/webaudio/ConstantSourceNode.cpp b/dom/media/webaudio/ConstantSourceNode.cpp
new file mode 100644
index 0000000000..01ee570722
--- /dev/null
+++ b/dom/media/webaudio/ConstantSourceNode.cpp
@@ -0,0 +1,279 @@
+/* -*- 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 "ConstantSourceNode.h"
+
+#include "AudioDestinationNode.h"
+#include "nsContentUtils.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeTrack.h"
+#include "Tracing.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(ConstantSourceNode, AudioScheduledSourceNode,
+                                   mOffset)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ConstantSourceNode)
+NS_INTERFACE_MAP_END_INHERITING(AudioScheduledSourceNode)
+
+NS_IMPL_ADDREF_INHERITED(ConstantSourceNode, AudioScheduledSourceNode)
+NS_IMPL_RELEASE_INHERITED(ConstantSourceNode, AudioScheduledSourceNode)
+
+class ConstantSourceNodeEngine final : public AudioNodeEngine {
+ public:
+  ConstantSourceNodeEngine(AudioNode* aNode, AudioDestinationNode* aDestination)
+      : AudioNodeEngine(aNode),
+        mSource(nullptr),
+        mDestination(aDestination->Track()),
+        mStart(-1),
+        mStop(TRACK_TIME_MAX)
+        // Keep the default values in sync with
+        // ConstantSourceNode::ConstantSourceNode.
+        ,
+        mOffset(1.0f) {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  void SetSourceTrack(AudioNodeTrack* aSource) { mSource = aSource; }
+
+  enum Parameters {
+    OFFSET,
+    START,
+    STOP,
+  };
+  void RecvTimelineEvent(uint32_t aIndex, AudioTimelineEvent& aEvent) override {
+    MOZ_ASSERT(mDestination);
+
+    WebAudioUtils::ConvertAudioTimelineEventToTicks(aEvent, mDestination);
+
+    switch (aIndex) {
+      case OFFSET:
+        mOffset.InsertEvent<int64_t>(aEvent);
+        break;
+      default:
+        NS_ERROR("Bad ConstantSourceNodeEngine TimelineParameter");
+    }
+  }
+
+  void SetTrackTimeParameter(uint32_t aIndex, TrackTime aParam) override {
+    switch (aIndex) {
+      case START:
+        mStart = aParam;
+        mSource->SetActive();
+        break;
+      case STOP:
+        mStop = aParam;
+        break;
+      default:
+        NS_ERROR("Bad ConstantSourceNodeEngine TrackTimeParameter");
+    }
+  }
+
+  void ProcessBlock(AudioNodeTrack* aTrack, GraphTime aFrom,
+                    const AudioBlock& aInput, AudioBlock* aOutput,
+                    bool* aFinished) override {
+    MOZ_ASSERT(mSource == aTrack, "Invalid source track");
+    TRACE("ConstantSourceNodeEngine::ProcessBlock");
+
+    TrackTime ticks = mDestination->GraphTimeToTrackTime(aFrom);
+    if (mStart == -1) {
+      aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
+      return;
+    }
+
+    if (ticks + WEBAUDIO_BLOCK_SIZE <= mStart || ticks >= mStop ||
+        mStop <= mStart) {
+      aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
+    } else {
+      aOutput->AllocateChannels(1);
+      float* output = aOutput->ChannelFloatsForWrite(0);
+      uint32_t writeOffset = 0;
+
+      if (ticks < mStart) {
+        MOZ_ASSERT(mStart - ticks <= WEBAUDIO_BLOCK_SIZE);
+        uint32_t count = mStart - ticks;
+        std::fill_n(output, count, 0.0f);
+        writeOffset += count;
+      }
+
+      MOZ_ASSERT(ticks + writeOffset >= mStart);
+      MOZ_ASSERT(mStop - ticks >= writeOffset);
+      uint32_t count =
+          std::min<TrackTime>(WEBAUDIO_BLOCK_SIZE, mStop - ticks) - writeOffset;
+
+      if (mOffset.HasSimpleValue()) {
+        float value = mOffset.GetValueAtTime(ticks);
+        std::fill_n(output + writeOffset, count, value);
+      } else {
+        mOffset.GetValuesAtTime(ticks + writeOffset, output + writeOffset,
+                                count);
+      }
+
+      writeOffset += count;
+
+      std::fill_n(output + writeOffset, WEBAUDIO_BLOCK_SIZE - writeOffset,
+                  0.0f);
+    }
+
+    if (ticks + WEBAUDIO_BLOCK_SIZE >= mStop) {
+      // We've finished playing.
+      *aFinished = true;
+    }
+  }
+
+  bool IsActive() const override {
+    // start() has been called.
+    return mStart != -1;
+  }
+
+  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override {
+    size_t amount = AudioNodeEngine::SizeOfExcludingThis(aMallocSizeOf);
+
+    // Not owned:
+    // - mSource
+    // - mDestination
+    // - mOffset (internal ref owned by node)
+
+    return amount;
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  // mSource deletes the engine in its destructor.
+  AudioNodeTrack* MOZ_NON_OWNING_REF mSource;
+  RefPtr<AudioNodeTrack> mDestination;
+  TrackTime mStart;
+  TrackTime mStop;
+  AudioParamTimeline mOffset;
+};
+
+ConstantSourceNode::ConstantSourceNode(AudioContext* aContext)
+    : AudioScheduledSourceNode(aContext, 2, ChannelCountMode::Max,
+                               ChannelInterpretation::Speakers),
+      mStartCalled(false) {
+  mOffset =
+      CreateAudioParam(ConstantSourceNodeEngine::OFFSET, u"offset"_ns, 1.0f);
+  ConstantSourceNodeEngine* engine =
+      new ConstantSourceNodeEngine(this, aContext->Destination());
+  mTrack = AudioNodeTrack::Create(aContext, engine,
+                                  AudioNodeTrack::NEED_MAIN_THREAD_ENDED,
+                                  aContext->Graph());
+  engine->SetSourceTrack(mTrack);
+  mTrack->AddMainThreadListener(this);
+}
+
+ConstantSourceNode::~ConstantSourceNode() = default;
+
+size_t ConstantSourceNode::SizeOfExcludingThis(
+    MallocSizeOf aMallocSizeOf) const {
+  size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
+
+  amount += mOffset->SizeOfIncludingThis(aMallocSizeOf);
+  return amount;
+}
+
+size_t ConstantSourceNode::SizeOfIncludingThis(
+    MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+JSObject* ConstantSourceNode::WrapObject(JSContext* aCx,
+                                         JS::Handle<JSObject*> aGivenProto) {
+  return ConstantSourceNode_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+already_AddRefed<ConstantSourceNode> ConstantSourceNode::Constructor(
+    const GlobalObject& aGlobal, AudioContext& aContext,
+    const ConstantSourceOptions& aOptions) {
+  RefPtr<ConstantSourceNode> object = new ConstantSourceNode(&aContext);
+  object->mOffset->SetInitialValue(aOptions.mOffset);
+  return object.forget();
+}
+
+void ConstantSourceNode::DestroyMediaTrack() {
+  if (mTrack) {
+    mTrack->RemoveMainThreadListener(this);
+  }
+  AudioNode::DestroyMediaTrack();
+}
+
+void ConstantSourceNode::Start(double aWhen, ErrorResult& aRv) {
+  if (!WebAudioUtils::IsTimeValid(aWhen)) {
+    aRv.ThrowRangeError<MSG_VALUE_OUT_OF_RANGE>("start time");
+    return;
+  }
+
+  if (mStartCalled) {
+    aRv.ThrowInvalidStateError("Can't call start() more than once");
+    return;
+  }
+  mStartCalled = true;
+
+  if (!mTrack) {
+    return;
+  }
+
+  mTrack->SetTrackTimeParameter(ConstantSourceNodeEngine::START, Context(),
+                                aWhen);
+
+  MarkActive();
+  Context()->StartBlockedAudioContextIfAllowed();
+}
+
+void ConstantSourceNode::Stop(double aWhen, ErrorResult& aRv) {
+  if (!WebAudioUtils::IsTimeValid(aWhen)) {
+    aRv.ThrowRangeError<MSG_VALUE_OUT_OF_RANGE>("stop time");
+    return;
+  }
+
+  if (!mStartCalled) {
+    aRv.ThrowInvalidStateError("Can't call stop() without calling start()");
+    return;
+  }
+
+  if (!mTrack || !Context()) {
+    return;
+  }
+
+  mTrack->SetTrackTimeParameter(ConstantSourceNodeEngine::STOP, Context(),
+                                std::max(0.0, aWhen));
+}
+
+void ConstantSourceNode::NotifyMainThreadTrackEnded() {
+  MOZ_ASSERT(mTrack->IsEnded());
+
+  class EndedEventDispatcher final : public Runnable {
+   public:
+    explicit EndedEventDispatcher(ConstantSourceNode* aNode)
+        : mozilla::Runnable("EndedEventDispatcher"), mNode(aNode) {}
+    NS_IMETHOD Run() override {
+      // If it's not safe to run scripts right now, schedule this to run later
+      if (!nsContentUtils::IsSafeToRunScript()) {
+        nsContentUtils::AddScriptRunner(this);
+        return NS_OK;
+      }
+
+      mNode->DispatchTrustedEvent(u"ended"_ns);
+      // Release track resources.
+      mNode->DestroyMediaTrack();
+      return NS_OK;
+    }
+
+   private:
+    RefPtr<ConstantSourceNode> mNode;
+  };
+
+  Context()->Dispatch(do_AddRef(new EndedEventDispatcher(this)));
+
+  // Drop the playing reference
+  // Warning: The below line might delete this.
+  MarkInactive();
+}
+
+}  // namespace mozilla::dom