1/*
2 * Copyright (C) 2012 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#include "config.h"
30
31#if ENABLE(WEB_AUDIO)
32
33#include "AudioPullFIFO.h"
34
35namespace WebCore {
36
37AudioPullFIFO::AudioPullFIFO(AudioSourceProvider& audioProvider, unsigned numberOfChannels, size_t fifoLength, size_t providerSize)
38    : m_provider(audioProvider)
39    , m_fifo(numberOfChannels, fifoLength)
40    , m_providerSize(providerSize)
41    , m_tempBus(AudioBus::create(numberOfChannels, providerSize))
42{
43}
44
45void AudioPullFIFO::consume(AudioBus* destination, size_t framesToConsume)
46{
47    if (!destination)
48        return;
49
50    if (framesToConsume > m_fifo.framesInFifo()) {
51        // We don't have enough data in the FIFO to fulfill the request. Ask for more data.
52        fillBuffer(framesToConsume - m_fifo.framesInFifo());
53    }
54
55    m_fifo.consume(destination, framesToConsume);
56}
57
58void AudioPullFIFO::fillBuffer(size_t numberOfFrames)
59{
60    // Keep asking the provider to give us data until we have received at least |numberOfFrames| of
61    // data. Stuff the data into the FIFO.
62    size_t framesProvided = 0;
63
64    while (framesProvided < numberOfFrames) {
65        m_provider.provideInput(m_tempBus.get(), m_providerSize);
66
67        m_fifo.push(m_tempBus.get());
68
69        framesProvided += m_providerSize;
70    }
71}
72
73} // namespace WebCore
74
75#endif // ENABLE(WEB_AUDIO)
76