1 files changed, 138 insertions, 0 deletions
diff --git a/dom/media/webaudio/AudioBuffer.h b/dom/media/webaudio/AudioBuffer.h
new file mode 100644
index 0000000000..e313c5c944
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+++ b/dom/media/webaudio/AudioBuffer.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 AudioBuffer_h_
+#define AudioBuffer_h_
+
+#include "AudioSegment.h"
+#include "nsWrapperCache.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/StaticMutex.h"
+#include "nsTArray.h"
+#include "js/TypeDecls.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/dom/TypedArray.h"
+#include "nsPIDOMWindow.h"
+#include "nsIWeakReferenceUtils.h"
+
+namespace mozilla {
+
+class ErrorResult;
+class ThreadSharedFloatArrayBufferList;
+
+namespace dom {
+
+struct AudioBufferOptions;
+
+/**
+ * An AudioBuffer keeps its data either in the mJSChannels objects, which
+ * are Float32Arrays, or in mSharedChannels if the mJSChannels objects' buffers
+ * are detached.
+ */
+class AudioBuffer final : public nsWrapperCache {
+ public:
+  // If non-null, aInitialContents must have number of channels equal to
+  // aNumberOfChannels and their lengths must be at least aLength.
+  static already_AddRefed<AudioBuffer> Create(
+      nsPIDOMWindowInner* aWindow, uint32_t aNumberOfChannels, uint32_t aLength,
+      float aSampleRate,
+      already_AddRefed<ThreadSharedFloatArrayBufferList> aInitialContents,
+      ErrorResult& aRv);
+
+  static already_AddRefed<AudioBuffer> Create(nsPIDOMWindowInner* aWindow,
+                                              uint32_t aNumberOfChannels,
+                                              uint32_t aLength,
+                                              float aSampleRate,
+                                              ErrorResult& aRv) {
+    return Create(aWindow, aNumberOfChannels, aLength, aSampleRate, nullptr,
+                  aRv);
+  }
+
+  // Non-unit AudioChunk::mVolume is not supported
+  static already_AddRefed<AudioBuffer> Create(nsPIDOMWindowInner* aWindow,
+                                              float aSampleRate,
+                                              AudioChunk&& aInitialContents);
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AudioBuffer)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AudioBuffer)
+
+  static already_AddRefed<AudioBuffer> Constructor(
+      const GlobalObject& aGlobal, const AudioBufferOptions& aOptions,
+      ErrorResult& aRv);
+
+  nsPIDOMWindowInner* GetParentObject() const {
+    nsCOMPtr<nsPIDOMWindowInner> parentObject = do_QueryReferent(mOwnerWindow);
+    return parentObject;
+  }
+
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+  float SampleRate() const { return mSampleRate; }
+
+  uint32_t Length() const { return mSharedChannels.mDuration; }
+
+  double Duration() const {
+    return Length() / static_cast<double>(mSampleRate);
+  }
+
+  uint32_t NumberOfChannels() const { return mJSChannels.Length(); }
+
+  /**
+   * If mSharedChannels is non-null, copies its contents to
+   * new Float32Arrays in mJSChannels. Returns a Float32Array.
+   */
+  void GetChannelData(JSContext* aJSContext, uint32_t aChannel,
+                      JS::MutableHandle<JSObject*> aRetval, ErrorResult& aRv);
+
+  void CopyFromChannel(const Float32Array& aDestination,
+                       uint32_t aChannelNumber, uint32_t aBufferOffset,
+                       ErrorResult& aRv);
+  void CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,
+                     uint32_t aChannelNumber, uint32_t aBufferOffset,
+                     ErrorResult& aRv);
+
+  /**
+   * Returns a reference to an AudioChunk containing the sample data.
+   * The AudioChunk can have a null buffer if there is no data.
+   */
+  const AudioChunk& GetThreadSharedChannelsForRate(JSContext* aContext);
+
+ protected:
+  AudioBuffer(nsPIDOMWindowInner* aWindow, uint32_t aNumberOfChannels,
+              uint32_t aLength, float aSampleRate, ErrorResult& aRv);
+  ~AudioBuffer();
+
+  void SetSharedChannels(
+      already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer);
+
+  bool RestoreJSChannelData(JSContext* aJSContext);
+
+  already_AddRefed<ThreadSharedFloatArrayBufferList>
+  StealJSArrayDataIntoSharedChannels(JSContext* aJSContext);
+
+  void ClearJSChannels();
+
+  // Float32Arrays
+  AutoTArray<JS::Heap<JSObject*>, 2> mJSChannels;
+  // mSharedChannels aggregates the data from mJSChannels. This is non-null
+  // if and only if the mJSChannels' buffers are detached, but its mDuration
+  // member keeps the buffer length regardless of whether the buffer is
+  // provided by mJSChannels or mSharedChannels.
+  AudioChunk mSharedChannels;
+
+  nsWeakPtr mOwnerWindow;
+  float mSampleRate;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif