1 files changed, 137 insertions, 0 deletions
diff --git a/dom/media/webaudio/AudioBuffer.h b/dom/media/webaudio/AudioBuffer.h
new file mode 100644
index 000000000..2f2aef5fe
--- /dev/null
+++ b/dom/media/webaudio/AudioBuffer.h
@@ -0,0 +1,137 @@
+/* -*- 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 "nsWrapperCache.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/StaticMutex.h"
+#include "nsTArray.h"
+#include "AudioContext.h"
+#include "js/TypeDecls.h"
+#include "mozilla/MemoryReporting.h"
+
+namespace mozilla {
+
+class ErrorResult;
+class ThreadSharedFloatArrayBufferList;
+
+namespace dom {
+
+class AudioContext;
+
+/**
+ * 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(AudioContext* aContext, uint32_t aNumberOfChannels,
+         uint32_t aLength, float aSampleRate,
+         already_AddRefed<ThreadSharedFloatArrayBufferList> aInitialContents,
+         ErrorResult& aRv);
+
+  static already_AddRefed<AudioBuffer>
+  Create(AudioContext* aContext, uint32_t aNumberOfChannels,
+         uint32_t aLength, float aSampleRate,
+         ErrorResult& aRv)
+  {
+    return Create(aContext, aNumberOfChannels, aLength, aSampleRate,
+                  nullptr, aRv);
+  }
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AudioBuffer)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AudioBuffer)
+
+  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 mLength;
+  }
+
+  double Duration() const
+  {
+    return mLength / 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 aStartInChannel, ErrorResult& aRv);
+  void CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,
+                     uint32_t aChannelNumber, uint32_t aStartInChannel,
+                     ErrorResult& aRv);
+
+  /**
+   * Returns a ThreadSharedFloatArrayBufferList containing the sample data.
+   * Can return null if there is no data.
+   */
+  ThreadSharedFloatArrayBufferList* GetThreadSharedChannelsForRate(JSContext* aContext);
+
+protected:
+  AudioBuffer(AudioContext* aContext, uint32_t aNumberOfChannels,
+              uint32_t aLength, float aSampleRate,
+              already_AddRefed<ThreadSharedFloatArrayBufferList>
+                aInitialContents);
+  ~AudioBuffer();
+
+  bool RestoreJSChannelData(JSContext* aJSContext);
+
+  already_AddRefed<ThreadSharedFloatArrayBufferList>
+  StealJSArrayDataIntoSharedChannels(JSContext* aJSContext);
+
+  void ClearJSChannels();
+
+  nsWeakPtr mOwnerWindow;
+  // 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.
+  RefPtr<ThreadSharedFloatArrayBufferList> mSharedChannels;
+
+  uint32_t mLength;
+  float mSampleRate;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif
+