1/*
2 * Copyright (C) 2010 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef HRTFDatabaseLoader_h
30#define HRTFDatabaseLoader_h
31
32#include "HRTFDatabase.h"
33#include <memory>
34#include <wtf/HashMap.h>
35#include <wtf/PassRefPtr.h>
36#include <wtf/RefCounted.h>
37#include <wtf/RefPtr.h>
38#include <wtf/Threading.h>
39
40namespace WebCore {
41
42// HRTFDatabaseLoader will asynchronously load the default HRTFDatabase in a new thread.
43
44class HRTFDatabaseLoader : public RefCounted<HRTFDatabaseLoader> {
45public:
46    // Lazily creates a HRTFDatabaseLoader (if not already created) for the given sample-rate
47    // and starts loading asynchronously (when created the first time).
48    // Returns the HRTFDatabaseLoader.
49    // Must be called from the main thread.
50    static PassRefPtr<HRTFDatabaseLoader> createAndLoadAsynchronouslyIfNecessary(float sampleRate);
51
52    // Both constructor and destructor must be called from the main thread.
53    ~HRTFDatabaseLoader();
54
55    // Returns true once the default database has been completely loaded.
56    bool isLoaded() const;
57
58    // waitForLoaderThreadCompletion() may be called more than once and is thread-safe.
59    void waitForLoaderThreadCompletion();
60
61    HRTFDatabase* database() { return m_hrtfDatabase.get(); }
62
63    float databaseSampleRate() const { return m_databaseSampleRate; }
64
65    // Called in asynchronous loading thread.
66    void load();
67
68private:
69    // Both constructor and destructor must be called from the main thread.
70    explicit HRTFDatabaseLoader(float sampleRate);
71
72    // If it hasn't already been loaded, creates a new thread and initiates asynchronous loading of the default database.
73    // This must be called from the main thread.
74    void loadAsynchronously();
75
76    std::unique_ptr<HRTFDatabase> m_hrtfDatabase;
77
78    // Holding a m_threadLock is required when accessing m_databaseLoaderThread.
79    Mutex m_threadLock;
80    ThreadIdentifier m_databaseLoaderThread;
81
82    float m_databaseSampleRate;
83};
84
85} // namespace WebCore
86
87#endif // HRTFDatabaseLoader_h
88