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* Copyright (C) 2012 Google Inc. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef AudioPullFIFO_h
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#define AudioPullFIFO_h
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#include "AudioFIFO.h"
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#include "AudioSourceProvider.h"
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// A FIFO (First In First Out) buffer to handle mismatches in buffer sizes between a provider and
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// receiver. The receiver will "pull" data from this FIFO. If data is already available in the
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// FIFO, it is provided to the receiver. If insufficient data is available to satisfy the request,
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// the FIFO will ask the provider for more data when necessary to fulfill a request. Contrast this
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// with a "push" FIFO, where the sender pushes data to the FIFO which will itself push the data to
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// the receiver when the FIFO is full.
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// Create a FIFO that gets data from |provider|. The FIFO will be large enough to hold
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// |fifoLength| frames of data of |numberOfChannels| channels. The AudioSourceProvider will be
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// asked to produce |providerSize| frames when the FIFO needs more data.
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AudioPullFIFO(AudioSourceProvider& audioProvider, unsigned numberOfChannels, size_t fifoLength, size_t providerSize);
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// Read |framesToConsume| frames from the FIFO into the destination. If the FIFO does not have
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// enough data, we ask the |provider| to get more data to fulfill the request.
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void consume(AudioBus* destination, size_t framesToConsume);
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// Fill the FIFO buffer with at least |numberOfFrames| more data.
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void fillBuffer(size_t numberOfFrames);
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// The provider of the data in our FIFO.
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AudioSourceProvider& m_provider;
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// Number of frames of data that the provider will produce per call.
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unsigned int m_providerSize;
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// Temporary workspace to hold the data from the provider.
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} // namespace WebCore
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#endif // AudioPullFIFO.h