/*
 * Copyright (C) 2010, Google Inc. All rights reserved.
 * Copyright (C) 2020-2021, Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1.  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "AudioDestinationNode.h"

#include "AudioBus.h"
#include "AudioContext.h"
#include "AudioIOCallback.h"
#include "AudioNodeInput.h"
#include "AudioNodeOutput.h"
#include "AudioUtilities.h"
#include "AudioWorklet.h"
#include "AudioWorkletGlobalScope.h"
#include "AudioWorkletMessagingProxy.h"
#include "AudioWorkletThread.h"
#include "DenormalDisabler.h"
#include <wtf/IsoMallocInlines.h>

namespace WebCore {
    
WTF_MAKE_ISO_ALLOCATED_IMPL(AudioDestinationNode);

AudioDestinationNode::AudioDestinationNode(BaseAudioContext& context, float sampleRate)
    : AudioNode(context, NodeTypeDestination)
    , m_sampleRate(sampleRate)
{
    addInput();
}

AudioDestinationNode::~AudioDestinationNode()
{
    uninitialize();
}

void AudioDestinationNode::renderQuantum(AudioBus* destinationBus, size_t numberOfFrames, const AudioIOPosition& outputPosition)
{
    // We don't want denormals slowing down any of the audio processing
    // since they can very seriously hurt performance.
    // This will take care of all AudioNodes because they all process within this scope.
    DenormalDisabler denormalDisabler;
    
    context().setAudioThread(Thread::current());

    // For performance reasons, we forbid heap allocations while doing rendering on the audio thread.
    // Heap allocations that cannot be avoided or have not been fixed yet can be allowed using
    // DisableMallocRestrictionsForCurrentThreadScope scope variables.
    ForbidMallocUseForCurrentThreadScope forbidMallocUse;
    
    if (!context().isInitialized()) {
        destinationBus->zero();
        return;
    }

    ASSERT(numberOfFrames);
    if (!numberOfFrames) {
        destinationBus->zero();
        return;
    }

    // Let the context take care of any business at the start of each render quantum.
    context().handlePreRenderTasks(outputPosition);

    RefPtr<AudioWorkletGlobalScope> workletGlobalScope;
    if (auto* audioWorkletProxy = context().audioWorklet().proxy())
        workletGlobalScope = audioWorkletProxy->workletThread().globalScope();
    if (workletGlobalScope)
        workletGlobalScope->handlePreRenderTasks();

    // This will cause the node(s) connected to us to process, which in turn will pull on their input(s),
    // all the way backwards through the rendering graph.
    AudioBus* renderedBus = input(0)->pull(destinationBus, numberOfFrames);

    if (!renderedBus)
        destinationBus->zero();
    else if (renderedBus != destinationBus) {
        // in-place processing was not possible - so copy
        destinationBus->copyFrom(*renderedBus);
    }

    // Process nodes which need a little extra help because they are not connected to anything, but still need to process.
    context().processAutomaticPullNodes(numberOfFrames);

    // Let the context take care of any business at the end of each render quantum.
    context().handlePostRenderTasks();
    
    // Advance current sample-frame.
    m_currentSampleFrame += numberOfFrames;

    if (workletGlobalScope)
        workletGlobalScope->handlePostRenderTasks(m_currentSampleFrame);
}

void AudioDestinationNode::ref()
{
    context().ref();
}

void AudioDestinationNode::deref()
{
    context().deref();
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)