Source/platform/audio/HRTFDatabaseLoader.cpp

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
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 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "platform/audio/HRTFDatabaseLoader.h"

#include "platform/Task.h"
#include "public/platform/Platform.h"
#include "wtf/MainThread.h"

namespace WebCore {

// Singleton
HRTFDatabaseLoader::LoaderMap* HRTFDatabaseLoader::s_loaderMap = 0;

PassRefPtr<HRTFDatabaseLoader> HRTFDatabaseLoader::createAndLoadAsynchronouslyIfNecessary(float sampleRate)
{
    ASSERT(isMainThread());

    RefPtr<HRTFDatabaseLoader> loader;

    if (!s_loaderMap)
        s_loaderMap = adoptPtr(new LoaderMap()).leakPtr();

    loader = s_loaderMap->get(sampleRate);
    if (loader) {
        ASSERT(sampleRate == loader->databaseSampleRate());
        return loader;
    }

    loader = adoptRef(new HRTFDatabaseLoader(sampleRate));
    s_loaderMap->add(sampleRate, loader.get());

    loader->loadAsynchronously();

    return loader;
}

HRTFDatabaseLoader::HRTFDatabaseLoader(float sampleRate)
    : m_databaseSampleRate(sampleRate)
{
    ASSERT(isMainThread());
}

HRTFDatabaseLoader::~HRTFDatabaseLoader()
{
    ASSERT(isMainThread());

    waitForLoaderThreadCompletion();
    m_hrtfDatabase.clear();

    // Remove ourself from the map.
    if (s_loaderMap)
        s_loaderMap->remove(m_databaseSampleRate);
}

void HRTFDatabaseLoader::load()
{
    ASSERT(!isMainThread());
    if (!m_hrtfDatabase) {
        // Load the default HRTF database.
        m_hrtfDatabase = HRTFDatabase::create(m_databaseSampleRate);
    }
}

void HRTFDatabaseLoader::loadAsynchronously()
{
    ASSERT(isMainThread());

    MutexLocker locker(m_threadLock);

    if (!m_hrtfDatabase && !m_databaseLoaderThread) {
        // Start the asynchronous database loading process.
        m_databaseLoaderThread = adoptPtr(blink::Platform::current()->createThread("HRTF database loader"));
        m_databaseLoaderThread->postTask(new Task(WTF::bind(&HRTFDatabaseLoader::load, this)));
    }
}

bool HRTFDatabaseLoader::isLoaded() const
{
    return m_hrtfDatabase;
}

void HRTFDatabaseLoader::waitForLoaderThreadCompletion()
{
    MutexLocker locker(m_threadLock);
    m_databaseLoaderThread.clear();
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)