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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim:set ts=2 sw=2 sts=2 et cindent: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #ifndef AudioBuffer_h_
       8             : #define AudioBuffer_h_
       9             : 
      10             : #include "nsWrapperCache.h"
      11             : #include "nsCycleCollectionParticipant.h"
      12             : #include "mozilla/Attributes.h"
      13             : #include "mozilla/StaticPtr.h"
      14             : #include "mozilla/StaticMutex.h"
      15             : #include "nsTArray.h"
      16             : #include "js/TypeDecls.h"
      17             : #include "mozilla/MemoryReporting.h"
      18             : #include "mozilla/dom/TypedArray.h"
      19             : 
      20             : namespace mozilla {
      21             : 
      22             : class ErrorResult;
      23             : class ThreadSharedFloatArrayBufferList;
      24             : 
      25             : namespace dom {
      26             : 
      27             : struct AudioBufferOptions;
      28             : 
      29             : /**
      30             :  * An AudioBuffer keeps its data either in the mJSChannels objects, which
      31             :  * are Float32Arrays, or in mSharedChannels if the mJSChannels objects' buffers
      32             :  * are detached.
      33             :  */
      34             : class AudioBuffer final : public nsWrapperCache
      35             : {
      36             : public:
      37             :   // If non-null, aInitialContents must have number of channels equal to
      38             :   // aNumberOfChannels and their lengths must be at least aLength.
      39             :   static already_AddRefed<AudioBuffer>
      40             :   Create(nsPIDOMWindowInner* aWindow, uint32_t aNumberOfChannels,
      41             :          uint32_t aLength, float aSampleRate,
      42             :          already_AddRefed<ThreadSharedFloatArrayBufferList> aInitialContents,
      43             :          ErrorResult& aRv);
      44             : 
      45             :   static already_AddRefed<AudioBuffer>
      46           0 :   Create(nsPIDOMWindowInner* aWindow, uint32_t aNumberOfChannels,
      47             :          uint32_t aLength, float aSampleRate,
      48             :          ErrorResult& aRv)
      49             :   {
      50             :     return Create(aWindow, aNumberOfChannels, aLength, aSampleRate,
      51           0 :                   nullptr, aRv);
      52             :   }
      53             : 
      54             :   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
      55             : 
      56           0 :   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AudioBuffer)
      57           0 :   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AudioBuffer)
      58             : 
      59             :   static already_AddRefed<AudioBuffer>
      60             :   Constructor(const GlobalObject& aGlobal,
      61             :               const AudioBufferOptions& aOptions, ErrorResult& aRv);
      62             : 
      63           0 :   nsPIDOMWindowInner* GetParentObject() const
      64             :   {
      65           0 :     nsCOMPtr<nsPIDOMWindowInner> parentObject = do_QueryReferent(mOwnerWindow);
      66           0 :     return parentObject;
      67             :   }
      68             : 
      69             :   JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
      70             : 
      71           0 :   float SampleRate() const
      72             :   {
      73           0 :     return mSampleRate;
      74             :   }
      75             : 
      76           0 :   uint32_t Length() const
      77             :   {
      78           0 :     return mLength;
      79             :   }
      80             : 
      81           0 :   double Duration() const
      82             :   {
      83           0 :     return mLength / static_cast<double> (mSampleRate);
      84             :   }
      85             : 
      86           0 :   uint32_t NumberOfChannels() const
      87             :   {
      88           0 :     return mJSChannels.Length();
      89             :   }
      90             : 
      91             :   /**
      92             :    * If mSharedChannels is non-null, copies its contents to
      93             :    * new Float32Arrays in mJSChannels. Returns a Float32Array.
      94             :    */
      95             :   void GetChannelData(JSContext* aJSContext, uint32_t aChannel,
      96             :                       JS::MutableHandle<JSObject*> aRetval,
      97             :                       ErrorResult& aRv);
      98             : 
      99             :   void CopyFromChannel(const Float32Array& aDestination, uint32_t aChannelNumber,
     100             :                        uint32_t aStartInChannel, ErrorResult& aRv);
     101             :   void CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,
     102             :                      uint32_t aChannelNumber, uint32_t aStartInChannel,
     103             :                      ErrorResult& aRv);
     104             : 
     105             :   /**
     106             :    * Returns a ThreadSharedFloatArrayBufferList containing the sample data.
     107             :    * Can return null if there is no data.
     108             :    */
     109             :   ThreadSharedFloatArrayBufferList* GetThreadSharedChannelsForRate(JSContext* aContext);
     110             : 
     111             : protected:
     112             :   AudioBuffer(nsPIDOMWindowInner* aWindow, uint32_t aNumberOfChannels,
     113             :               uint32_t aLength, float aSampleRate,
     114             :               already_AddRefed<ThreadSharedFloatArrayBufferList>
     115             :                 aInitialContents);
     116             :   ~AudioBuffer();
     117             : 
     118             :   bool RestoreJSChannelData(JSContext* aJSContext);
     119             : 
     120             :   already_AddRefed<ThreadSharedFloatArrayBufferList>
     121             :   StealJSArrayDataIntoSharedChannels(JSContext* aJSContext);
     122             : 
     123             :   void ClearJSChannels();
     124             : 
     125             :   nsWeakPtr mOwnerWindow;
     126             :   // Float32Arrays
     127             :   AutoTArray<JS::Heap<JSObject*>, 2> mJSChannels;
     128             : 
     129             :   // mSharedChannels aggregates the data from mJSChannels. This is non-null
     130             :   // if and only if the mJSChannels' buffers are detached.
     131             :   RefPtr<ThreadSharedFloatArrayBufferList> mSharedChannels;
     132             : 
     133             :   uint32_t mLength;
     134             :   float mSampleRate;
     135             : };
     136             : 
     137             : } // namespace dom
     138             : } // namespace mozilla
     139             : 
     140             : #endif