#ifndef DPTUTFENCODE_H
#define DPTUTFENCODE_H

typedef unsigned int u32;

class IDptByteEncode {
public:
  int Encode(unsigned char *b, u32 val);
  int Decode(const unsigned char *b, u32 &val);
};

// Iterator class which uses above encoding and runlength encoding of zeroes

class IDptByteEncodeItr {
 public:
  IDptByteEncodeItr(unsigned char *buff) : fZeros(0), fEndPtr(buff), 
                              fZeroPtr(NULL) {}     // ctor
  unsigned char *GetEndPtr() { return fEndPtr; }
  void Insert(u32 val);
  void InsertEndMark() { *fEndPtr = 0xFE; fEndPtr++; fZeros=0; }

 private:
  IDptByteEncode e; // Just a clump of histograms
  u32 fZeros;      // Number of zeros in current run
  unsigned char *fEndPtr;   // Pointer to the first unused location  
  unsigned char *fZeroPtr;  // Pointer to the current zeros record
};

// Companion decoder for DptByteEncodeItr
// To use,
// Call ctor
// while (I want another histogram) {
//   Loop nbins times, call GetNextValue
//   GetState, if 0, continue, if 1 we have finished spot on, 
//                             if 2 we have overrun, if 3 something bad happened and we cheerfully returned 0 to some of the calls
// }
class IDptByteDecodeItr {
 public:
  IDptByteDecodeItr(const unsigned char *buff) 
      : fZeros(0), fEndPtr(buff), fState(0) {}
  const unsigned char *GetEndPtr() { return fEndPtr; }
  int GetState() { return fState; }
  u32 GetNextValue();
  int IsNextAnEndMark() { return ((*fEndPtr)==0xFE); }
  
 private:
  IDptByteEncode e; // Just a clump of histograms
  u32 fZeros;      // Number of zeros issued so far this run
  const unsigned char *fEndPtr;   // Pointer to the first unused location
  int fState;      // Status: 0=Normal, 1 = reached end OK, 
                   //         2 = read beyond end, 3 = error in decoding
};

#endif