ECCFill_C1.h

//
// Copyright 2018, Jeremy Cooper
// All rights reserved.
//
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// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
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#ifndef RDAT_ECCFILL_C1_H
#define RDAT_ECCFILL_C1_H

#include "ECCIterator.h"
#include "Track.h"

//
// This class encapsulates the way in which DAT's C1 error correction
// scheme interprets the bytes from a Track object to be corrected.
//
class ECCFill_C1 : public ECCIterator {
public:
  //
  // Prepare an ECC session for an entire Track.
  //
  ECCFill_C1(Track& track);
  
  //
  // Query the current position.
  //
  bool CurrentPosition(unsigned int& block, unsigned int& offset);

  ////////////////////////////////////////////////////////////////////////////
  // Methods from parent ECCIterator interface.
  
  //
  // Advance to the next vector. For C1 this means choosing the other
  // interleave set for a track pair, or advancing to the next block pair.
  //
  bool Next();
  
  //
  // Query this iterator to determine if it has completed its run.
  //
  bool End() const;
  
  // End methods from parent ECCIterator interface.
  ////////////////////////////////////////////////////////////////////////////

  ////////////////////////////////////////////////////////////////////////////
  // Methods from grandparent ECCFill interface.

  uint8_t& Data(size_t position);
  bool&    Valid(size_t position);

  // End methods from grandparent ECCFill interface.
  ////////////////////////////////////////////////////////////////////////////
  
protected:
  //
  // A reference to the underlying data block array from the track whence
  // these bytes come and to which they go once they are corrected.
  //
  Track::DataArray& mData;
  Track::ValidityArray& mDataIsValid;
  
  //
  // The block number of the lower member of the block pair that is being
  // evaluated.
  //
  unsigned int mBlockPairStart;
  
  //
  // Which stream, even or odd, is being interpreted in this fill.
  //
  typedef enum {
    EVEN,
    ODD
  } Even;
  Even mInterleaveSet;
};

#endif