The Tor Browser: content/media/webaudio/ConvolverNode.cpp@97036ab72558 (annotated)

content/media/webaudio/ConvolverNode.cpp@97036ab72558 (annotated)

content/media/webaudio/ConvolverNode.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- 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/. */
 #include "ConvolverNode.h"
 #include "mozilla/dom/ConvolverNodeBinding.h"
 #include "AudioNodeEngine.h"
 #include "AudioNodeStream.h"
 #include "blink/Reverb.h"
 #include "PlayingRefChangeHandler.h"
 namespace mozilla {
 namespace dom {
 NS_IMPL_CYCLE_COLLECTION_INHERITED(ConvolverNode, AudioNode, mBuffer)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ConvolverNode)
 NS_INTERFACE_MAP_END_INHERITING(AudioNode)
 NS_IMPL_ADDREF_INHERITED(ConvolverNode, AudioNode)
 NS_IMPL_RELEASE_INHERITED(ConvolverNode, AudioNode)
 class ConvolverNodeEngine : public AudioNodeEngine
 {
   typedef PlayingRefChangeHandler PlayingRefChanged;
 public:
   ConvolverNodeEngine(AudioNode* aNode, bool aNormalize)
     : AudioNodeEngine(aNode)
     , mBufferLength(0)
     , mLeftOverData(INT32_MIN)
     , mSampleRate(0.0f)
     , mUseBackgroundThreads(!aNode->Context()->IsOffline())
     , mNormalize(aNormalize)
   {
   }
   enum Parameters {
     BUFFER_LENGTH,
     SAMPLE_RATE,
     NORMALIZE
   };
   virtual void SetInt32Parameter(uint32_t aIndex, int32_t aParam) MOZ_OVERRIDE
   {
     switch (aIndex) {
     case BUFFER_LENGTH:
       // BUFFER_LENGTH is the first parameter that we set when setting a new buffer,
       // so we should be careful to invalidate the rest of our state here.
       mBuffer = nullptr;
       mSampleRate = 0.0f;
       mBufferLength = aParam;
       mLeftOverData = INT32_MIN;
       break;
     case SAMPLE_RATE:
       mSampleRate = aParam;
       break;
     case NORMALIZE:
       mNormalize = !!aParam;
       break;
     default:
       NS_ERROR("Bad ConvolverNodeEngine Int32Parameter");
     }
   }
   virtual void SetDoubleParameter(uint32_t aIndex, double aParam) MOZ_OVERRIDE
   {
     switch (aIndex) {
     case SAMPLE_RATE:
       mSampleRate = aParam;
       AdjustReverb();
       break;
     default:
       NS_ERROR("Bad ConvolverNodeEngine DoubleParameter");
     }
   }
   virtual void SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer)
   {
     mBuffer = aBuffer;
     AdjustReverb();
   }
   void AdjustReverb()
   {
     // Note about empirical tuning (this is copied from Blink)
     // The maximum FFT size affects reverb performance and accuracy.
     // If the reverb is single-threaded and processes entirely in the real-time audio thread,
     // it's important not to make this too high.  In this case 8192 is a good value.
     // But, the Reverb object is multi-threaded, so we want this as high as possible without losing too much accuracy.
     // Very large FFTs will have worse phase errors. Given these constraints 32768 is a good compromise.
     const size_t MaxFFTSize = 32768;
     if (!mBuffer || !mBufferLength || !mSampleRate) {
       mReverb = nullptr;
       mLeftOverData = INT32_MIN;
       return;
     }
     mReverb = new WebCore::Reverb(mBuffer, mBufferLength,
                                   WEBAUDIO_BLOCK_SIZE,
                                   MaxFFTSize, 2, mUseBackgroundThreads,
                                   mNormalize, mSampleRate);
   }
   virtual void ProcessBlock(AudioNodeStream* aStream,
                             const AudioChunk& aInput,
                             AudioChunk* aOutput,
                             bool* aFinished)
   {
     if (!mReverb) {
       *aOutput = aInput;
       return;
     }
     AudioChunk input = aInput;
     if (aInput.IsNull()) {
       if (mLeftOverData > 0) {
         mLeftOverData -= WEBAUDIO_BLOCK_SIZE;
         AllocateAudioBlock(1, &input);
         WriteZeroesToAudioBlock(&input, 0, WEBAUDIO_BLOCK_SIZE);
       } else {
         if (mLeftOverData != INT32_MIN) {
           mLeftOverData = INT32_MIN;
           nsRefPtr<PlayingRefChanged> refchanged =
             new PlayingRefChanged(aStream, PlayingRefChanged::RELEASE);
           aStream->Graph()->
             DispatchToMainThreadAfterStreamStateUpdate(refchanged.forget());
         }
         aOutput->SetNull(WEBAUDIO_BLOCK_SIZE);
         return;
       }
     } else {
       if (aInput.mVolume != 1.0f) {
         // Pre-multiply the input's volume
         uint32_t numChannels = aInput.mChannelData.Length();
         AllocateAudioBlock(numChannels, &input);
         for (uint32_t i = 0; i < numChannels; ++i) {
           const float* src = static_cast<const float*>(aInput.mChannelData[i]);
           float* dest = static_cast<float*>(const_cast<void*>(input.mChannelData[i]));
           AudioBlockCopyChannelWithScale(src, aInput.mVolume, dest);
         }
       }
       if (mLeftOverData <= 0) {
         nsRefPtr<PlayingRefChanged> refchanged =
           new PlayingRefChanged(aStream, PlayingRefChanged::ADDREF);
         aStream->Graph()->
           DispatchToMainThreadAfterStreamStateUpdate(refchanged.forget());
       }
       mLeftOverData = mBufferLength;
       MOZ_ASSERT(mLeftOverData > 0);
     }
     AllocateAudioBlock(2, aOutput);
     mReverb->process(&input, aOutput, WEBAUDIO_BLOCK_SIZE);
   }
   virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
   {
     size_t amount = AudioNodeEngine::SizeOfExcludingThis(aMallocSizeOf);
     if (mBuffer && !mBuffer->IsShared()) {
       amount += mBuffer->SizeOfIncludingThis(aMallocSizeOf);
     }
     if (mReverb) {
       amount += mReverb->sizeOfIncludingThis(aMallocSizeOf);
     }
     return amount;
   }
   virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
   {
     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
   }
 private:
   nsRefPtr<ThreadSharedFloatArrayBufferList> mBuffer;
   nsAutoPtr<WebCore::Reverb> mReverb;
   int32_t mBufferLength;
   int32_t mLeftOverData;
   float mSampleRate;
   bool mUseBackgroundThreads;
   bool mNormalize;
 };
 ConvolverNode::ConvolverNode(AudioContext* aContext)
   : AudioNode(aContext,
 ,
               ChannelCountMode::Clamped_max,
               ChannelInterpretation::Speakers)
   , mNormalize(true)
 {
   ConvolverNodeEngine* engine = new ConvolverNodeEngine(this, mNormalize);
   mStream = aContext->Graph()->CreateAudioNodeStream(engine, MediaStreamGraph::INTERNAL_STREAM);
 }
 size_t
 ConvolverNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
 {
   size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
   if (mBuffer) {
     // NB: mBuffer might be shared with the associated engine, by convention
     //     the AudioNode will report.
     amount += mBuffer->SizeOfIncludingThis(aMallocSizeOf);
   }
   return amount;
 }
 size_t
 ConvolverNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
 {
   return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
 }
 JSObject*
 ConvolverNode::WrapObject(JSContext* aCx)
 {
   return ConvolverNodeBinding::Wrap(aCx, this);
 }
 void
 ConvolverNode::SetBuffer(JSContext* aCx, AudioBuffer* aBuffer, ErrorResult& aRv)
 {
   if (aBuffer) {
     switch (aBuffer->NumberOfChannels()) {
     case 1:
     case 2:
     case 4:
       // Supported number of channels
       break;
     default:
       aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
       return;
     }
   }
   mBuffer = aBuffer;
   // Send the buffer to the stream
   AudioNodeStream* ns = static_cast<AudioNodeStream*>(mStream.get());
   MOZ_ASSERT(ns, "Why don't we have a stream here?");
   if (mBuffer) {
     uint32_t length = mBuffer->Length();
     nsRefPtr<ThreadSharedFloatArrayBufferList> data =
       mBuffer->GetThreadSharedChannelsForRate(aCx);
     if (data && length < WEBAUDIO_BLOCK_SIZE) {
       // For very small impulse response buffers, we need to pad the
       // buffer with 0 to make sure that the Reverb implementation
       // has enough data to compute FFTs from.
       length = WEBAUDIO_BLOCK_SIZE;
       nsRefPtr<ThreadSharedFloatArrayBufferList> paddedBuffer =
         new ThreadSharedFloatArrayBufferList(data->GetChannels());
       float* channelData = (float*) malloc(sizeof(float) * length * data->GetChannels());
       for (uint32_t i = 0; i < data->GetChannels(); ++i) {
         PodCopy(channelData + length * i, data->GetData(i), mBuffer->Length());
         PodZero(channelData + length * i + mBuffer->Length(), WEBAUDIO_BLOCK_SIZE - mBuffer->Length());
         paddedBuffer->SetData(i, (i == 0) ? channelData : nullptr, channelData);
       }
       data = paddedBuffer;
     }
     SendInt32ParameterToStream(ConvolverNodeEngine::BUFFER_LENGTH, length);
     SendDoubleParameterToStream(ConvolverNodeEngine::SAMPLE_RATE,
                                 mBuffer->SampleRate());
     ns->SetBuffer(data.forget());
   } else {
     ns->SetBuffer(nullptr);
   }
 }
 void
 ConvolverNode::SetNormalize(bool aNormalize)
 {
   mNormalize = aNormalize;
   SendInt32ParameterToStream(ConvolverNodeEngine::NORMALIZE, aNormalize);
 }
 }
 }

The Tor Browser / annotate

content/media/webaudio/ConvolverNode.cpp@97036ab72558 (annotated)

content/media/webaudio/ConvolverNode.cpp