HRTFDatabaseLoader.cpp   [plain text]

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions
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 *
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 *     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
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "HRTFDatabaseLoader.h"

#include "HRTFDatabase.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_databaseLoaderThread(0)
    , 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);
}

// Asynchronously load the database in this thread.
static void databaseLoaderEntry(void* threadData)
{
    HRTFDatabaseLoader* loader = reinterpret_cast<HRTFDatabaseLoader*>(threadData);
    ASSERT(loader);
    loader->load();
}

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

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

    MutexLocker locker(m_threadLock);
    
    if (!m_hrtfDatabase.get() && !m_databaseLoaderThread) {
        // Start the asynchronous database loading process.
        m_databaseLoaderThread = createThread(databaseLoaderEntry, this, "HRTF database loader");
    }
}

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

void HRTFDatabaseLoader::waitForLoaderThreadCompletion()
{
    MutexLocker locker(m_threadLock);
    
    // waitForThreadCompletion() should not be called twice for the same thread.
    if (m_databaseLoaderThread)
        waitForThreadCompletion(m_databaseLoaderThread);
    m_databaseLoaderThread = 0;
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)