1 files changed, 294 insertions, 0 deletions
diff --git a/dom/media/webaudio/AudioNode.h b/dom/media/webaudio/AudioNode.h
new file mode 100644
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+++ b/dom/media/webaudio/AudioNode.h
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+/* -*- 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/. */
+
+#ifndef AudioNode_h_
+#define AudioNode_h_
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/AudioNodeBinding.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsTArray.h"
+#include "AudioContext.h"
+#include "MediaStreamGraph.h"
+#include "WebAudioUtils.h"
+#include "mozilla/MemoryReporting.h"
+#include "nsWeakReference.h"
+#include "SelfRef.h"
+
+namespace mozilla {
+
+namespace dom {
+
+class AudioContext;
+class AudioBufferSourceNode;
+class AudioParam;
+class AudioParamTimeline;
+struct ThreeDPoint;
+
+/**
+ * The DOM object representing a Web Audio AudioNode.
+ *
+ * Each AudioNode has a MediaStream representing the actual
+ * real-time processing and output of this AudioNode.
+ *
+ * We track the incoming and outgoing connections to other AudioNodes.
+ * Outgoing connections have strong ownership.  Also, AudioNodes that will
+ * produce sound on their output even when they have silent or no input ask
+ * the AudioContext to keep playing or tail-time references to keep them alive
+ * until the context is finished.
+ *
+ * Explicit disconnections will only remove references from output nodes after
+ * the graph is notified and the main thread receives a reply.  Similarly,
+ * nodes with playing or tail-time references release these references only
+ * after receiving notification from their engine on the graph thread that
+ * playing has stopped.  Engines notifying the main thread that they have
+ * finished do so strictly *after* producing and returning their last block.
+ * In this way, an engine that receives non-null input knows that the input
+ * comes from nodes that are still alive and will keep their output nodes
+ * alive for at least as long as it takes to process messages from the graph
+ * thread.  i.e. the engine receiving non-null input knows that its node is
+ * still alive, and will still be alive when it receives a message from the
+ * engine.
+ */
+class AudioNode : public DOMEventTargetHelper,
+                  public nsSupportsWeakReference
+{
+protected:
+  // You can only use refcounting to delete this object
+  virtual ~AudioNode();
+
+public:
+  AudioNode(AudioContext* aContext,
+            uint32_t aChannelCount,
+            ChannelCountMode aChannelCountMode,
+            ChannelInterpretation aChannelInterpretation);
+
+  // This should be idempotent (safe to call multiple times).
+  virtual void DestroyMediaStream();
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AudioNode,
+                                           DOMEventTargetHelper)
+
+  virtual AudioBufferSourceNode* AsAudioBufferSourceNode()
+  {
+    return nullptr;
+  }
+
+  AudioContext* GetParentObject() const
+  {
+    return mContext;
+  }
+
+  AudioContext* Context() const
+  {
+    return mContext;
+  }
+
+  virtual AudioNode* Connect(AudioNode& aDestination, uint32_t aOutput,
+                             uint32_t aInput, ErrorResult& aRv);
+
+  virtual void Connect(AudioParam& aDestination, uint32_t aOutput,
+                       ErrorResult& aRv);
+
+  virtual void Disconnect(ErrorResult& aRv);
+  virtual void Disconnect(uint32_t aOutput, ErrorResult& aRv);
+  virtual void Disconnect(AudioNode& aDestination, ErrorResult& aRv);
+  virtual void Disconnect(AudioNode& aDestination, uint32_t aOutput,
+                          ErrorResult& aRv);
+  virtual void Disconnect(AudioNode& aDestination,
+                          uint32_t aOutput, uint32_t aInput,
+                          ErrorResult& aRv);
+  virtual void Disconnect(AudioParam& aDestination, ErrorResult& aRv);
+  virtual void Disconnect(AudioParam& aDestination, uint32_t aOutput,
+                          ErrorResult& aRv);
+
+  // Called after input nodes have been explicitly added or removed through
+  // the Connect() or Disconnect() methods.
+  virtual void NotifyInputsChanged() {}
+  // Indicate that the node should continue indefinitely to behave as if an
+  // input is connected, even though there is no longer a corresponding entry
+  // in mInputNodes.  Called after an input node has been removed because it
+  // is being garbage collected.
+  virtual void NotifyHasPhantomInput() {}
+
+  // The following two virtual methods must be implemented by each node type
+  // to provide their number of input and output ports. These numbers are
+  // constant for the lifetime of the node. Both default to 1.
+  virtual uint16_t NumberOfInputs() const { return 1; }
+  virtual uint16_t NumberOfOutputs() const { return 1; }
+
+  uint32_t Id() const { return mId; }
+
+  bool PassThrough() const;
+  void SetPassThrough(bool aPassThrough);
+
+  uint32_t ChannelCount() const { return mChannelCount; }
+  virtual void SetChannelCount(uint32_t aChannelCount, ErrorResult& aRv)
+  {
+    if (aChannelCount == 0 ||
+        aChannelCount > WebAudioUtils::MaxChannelCount) {
+      aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+      return;
+    }
+    mChannelCount = aChannelCount;
+    SendChannelMixingParametersToStream();
+  }
+  ChannelCountMode ChannelCountModeValue() const
+  {
+    return mChannelCountMode;
+  }
+  virtual void SetChannelCountModeValue(ChannelCountMode aMode, ErrorResult& aRv)
+  {
+    mChannelCountMode = aMode;
+    SendChannelMixingParametersToStream();
+  }
+  ChannelInterpretation ChannelInterpretationValue() const
+  {
+    return mChannelInterpretation;
+  }
+  void SetChannelInterpretationValue(ChannelInterpretation aMode)
+  {
+    mChannelInterpretation = aMode;
+    SendChannelMixingParametersToStream();
+  }
+
+  struct InputNode final
+  {
+    ~InputNode()
+    {
+      if (mStreamPort) {
+        mStreamPort->Destroy();
+      }
+    }
+
+    size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
+    {
+      size_t amount = 0;
+      if (mStreamPort) {
+        amount += mStreamPort->SizeOfIncludingThis(aMallocSizeOf);
+      }
+
+      return amount;
+    }
+
+    // Weak reference.
+    AudioNode* mInputNode;
+    RefPtr<MediaInputPort> mStreamPort;
+    // The index of the input port this node feeds into.
+    // This is not used for connections to AudioParams.
+    uint32_t mInputPort;
+    // The index of the output port this node comes out of.
+    uint32_t mOutputPort;
+  };
+
+  // Returns the stream, if any.
+  AudioNodeStream* GetStream() const { return mStream; }
+
+  const nsTArray<InputNode>& InputNodes() const
+  {
+    return mInputNodes;
+  }
+  const nsTArray<RefPtr<AudioNode> >& OutputNodes() const
+  {
+    return mOutputNodes;
+  }
+  const nsTArray<RefPtr<AudioParam> >& OutputParams() const
+  {
+    return mOutputParams;
+  }
+
+  template<typename T>
+  const nsTArray<InputNode>&
+  InputsForDestination(uint32_t aOutputIndex) const;
+
+  void RemoveOutputParam(AudioParam* aParam);
+
+  // MarkActive() asks the context to keep the AudioNode alive until the
+  // context is finished.  This takes care of "playing" references and
+  // "tail-time" references.
+  void MarkActive() { Context()->RegisterActiveNode(this); }
+  // Active nodes call MarkInactive() when they have finished producing sound
+  // for the foreseeable future.
+  // Do not call MarkInactive from a node destructor.  If the destructor is
+  // called, then the node is already inactive.
+  // MarkInactive() may delete |this|.
+  void MarkInactive() { Context()->UnregisterActiveNode(this); }
+
+  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const;
+  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
+
+  // Returns a string from constant static storage identifying the dom node
+  // type.
+  virtual const char* NodeType() const = 0;
+
+private:
+  // Given:
+  //
+  // - a DestinationType, that can be an AudioNode or an AudioParam ;
+  // - a Predicate, a function that takes an InputNode& and returns a bool ;
+  //
+  // This method iterates on the InputNodes() of the node at the index
+  // aDestinationIndex, and calls `DisconnectFromOutputIfConnected` with this
+  // input node, if aPredicate returns true.
+  template<typename DestinationType, typename Predicate>
+  bool DisconnectMatchingDestinationInputs(uint32_t aDestinationIndex,
+                                           Predicate aPredicate);
+
+  virtual void LastRelease() override
+  {
+    // We are about to be deleted, disconnect the object from the graph before
+    // the derived type is destroyed.
+    DisconnectFromGraph();
+  }
+  // Callers must hold a reference to 'this'.
+  void DisconnectFromGraph();
+
+  template<typename DestinationType>
+  bool DisconnectFromOutputIfConnected(uint32_t aOutputIndex, uint32_t aInputIndex);
+
+protected:
+  // Helpers for sending different value types to streams
+  void SendDoubleParameterToStream(uint32_t aIndex, double aValue);
+  void SendInt32ParameterToStream(uint32_t aIndex, int32_t aValue);
+  void SendThreeDPointParameterToStream(uint32_t aIndex, const ThreeDPoint& aValue);
+  void SendChannelMixingParametersToStream();
+
+private:
+  RefPtr<AudioContext> mContext;
+
+protected:
+  // Must be set in the constructor. Must not be null unless finished.
+  RefPtr<AudioNodeStream> mStream;
+
+private:
+  // For every InputNode, there is a corresponding entry in mOutputNodes of the
+  // InputNode's mInputNode.
+  nsTArray<InputNode> mInputNodes;
+  // For every mOutputNode entry, there is a corresponding entry in mInputNodes
+  // of the mOutputNode entry. We won't necessarily be able to identify the
+  // exact matching entry, since mOutputNodes doesn't include the port
+  // identifiers and the same node could be connected on multiple ports.
+  nsTArray<RefPtr<AudioNode> > mOutputNodes;
+  // For every mOutputParams entry, there is a corresponding entry in
+  // AudioParam::mInputNodes of the mOutputParams entry. We won't necessarily be
+  // able to identify the exact matching entry, since mOutputParams doesn't
+  // include the port identifiers and the same node could be connected on
+  // multiple ports.
+  nsTArray<RefPtr<AudioParam> > mOutputParams;
+  uint32_t mChannelCount;
+  ChannelCountMode mChannelCountMode;
+  ChannelInterpretation mChannelInterpretation;
+  const uint32_t mId;
+  // Whether the node just passes through its input.  This is a devtools API that
+  // only works for some node types.
+  bool mPassThrough;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif