/* -*- 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 aStartInChannel, ErrorResult& aRv);

  void CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,

                     uint32_t aChannelNumber, uint32_t aStartInChannel,

                     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