Introduce PushPullFIFO class and remove other FIFOs

third_party/WebKit/Source/platform/audio/AudioPullFIFO.h

-/*
- * Copyright (C) 2012 Google Inc. All rights reserved.
- *
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- * modification, are permitted provided that the following conditions
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- *     notice, this list of conditions and the following disclaimer.
- * 2.  Redistributions in binary form must reproduce the above copyright
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- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
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-
-#ifndef AudioPullFIFO_h
-#define AudioPullFIFO_h
-
-#include "platform/audio/AudioBus.h"
-#include "platform/audio/AudioFIFO.h"
-#include "platform/audio/AudioSourceProvider.h"
-#include "wtf/Allocator.h"
-
-namespace blink {
-
-// A FIFO (First In First Out) buffer to handle mismatches in buffer sizes
-// between a provider and receiver. The receiver will "pull" data from this
-// FIFO. If data is already available in the FIFO, it is provided to the
-// receiver. If insufficient data is available to satisfy the request, the FIFO
-// will ask the provider for more data when necessary to fulfill a request.
-// Contrast this with a "push" FIFO, where the sender pushes data to the FIFO
-// which will itself push the data to the receiver when the FIFO is full.
-class PLATFORM_EXPORT AudioPullFIFO {
-  USING_FAST_MALLOC(AudioPullFIFO);
-  WTF_MAKE_NONCOPYABLE(AudioPullFIFO);
-
- public:
-  // Create a FIFO that gets data from |provider|. The FIFO will be large
-  // enough to hold |fifoLength| frames of data of |numberOfChannels| channels.
-  // The AudioSourceProvider will be asked to produce |providerSize| frames
-  // when the FIFO needs more data.
-  AudioPullFIFO(AudioSourceProvider& audioProvider,
-                unsigned numberOfChannels,
-                size_t fifoLength,
-                size_t providerSize);
-
-  // Read |framesToConsume| frames from the FIFO into the destination. If the
-  // FIFO does not have enough data, we ask the |provider| to get more data to
-  // fulfill the request.
-  void consume(AudioBus* destination, size_t framesToConsume);
-
- private:
-  // Fill the FIFO buffer with at least |numberOfFrames| more data.
-  void fillBuffer(size_t numberOfFrames);
-
-  // The provider of the data in our FIFO.
-  AudioSourceProvider& m_provider;
-
-  // The actual FIFO
-  AudioFIFO m_fifo;
-
-  // Number of frames of data that the provider will produce per call.
-  unsigned m_providerSize;
-
-  // Temporary workspace to hold the data from the provider.
-  RefPtr<AudioBus> m_tempBus;
-};
-
-}  // namespace blink
-
-#endif  // AudioPullFIFO.h