RingBuffer.h

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  RingBuffer.h
 
  Dominic Mazzoni
 
*******************************************************************/
 
#ifndef __AUDACITY_RING_BUFFER__
#define __AUDACITY_RING_BUFFER__
 
#include "SampleFormat.h"
#include <atomic>
 
class RingBuffer final : public NonInterferingBase {
 public:
   RingBuffer(sampleFormat format, size_t size);
   ~RingBuffer();
 
   //
   // For the writer only:
   //
 
   size_t AvailForPut() const;
   size_t WrittenForGet() const;
   size_t Put(constSamplePtr buffer, sampleFormat format, size_t samples,
              // optional number of trailing zeroes
              size_t padding = 0);
 
   size_t Unput(size_t size);
   size_t Clear(sampleFormat format, size_t samples);
   std::pair<samplePtr, size_t> GetUnflushed(unsigned iBlock);
   void Flush();
 
   //
   // For the reader only:
   //
 
   size_t AvailForGet() const;
   size_t Get(samplePtr buffer, sampleFormat format, size_t samples);
   size_t Discard(size_t samples);
 
 private:
   size_t Filled(size_t start, size_t end) const;
   size_t Free(size_t start, size_t end) const;
 
   size_t mWritten{0};
   size_t mLastPadding{0};
 
   // Align the two atomics to avoid false sharing
   NonInterfering< std::atomic<size_t> > mStart{ 0 }, mEnd{ 0 };
 
   const size_t  mBufferSize;
 
   const sampleFormat  mFormat;
   const SampleBuffer  mBuffer;
};
 
#endif /*  __AUDACITY_RING_BUFFER__ */