literalhufftree.h

My (so called) HiP compression algorithm as console mode utility. It s a hybrid of Lempel-Ziv 77 a

/*****************************************************************************

  LiteralHuffTree
  ---------------

  Class for generating/emitting Huffman trees on a byte base.
  Could be used for adaptive and non-adaptive Huffman tree models.

  by yoda

  WWW:      y0da.cjb.net
  E-mail:   [e-mail]

  You are allowed to use this class in your own projects if you keep this
  trademark.

*****************************************************************************/

#pragma once

#include <windows.h>
#include "ByteReader.h"

//
// constants
//
#define HT_LEFT  0
#define HT_RIGHT 1

//
// structures
//
typedef struct _LHT_ITEM
{
	WORD                     id;                           // a unique value
	BOOL                     bLinked;                      // already linked in the tree ?
	DWORD                    dwDadId;                      // 0 == root item
	DWORD                    dwLeftId;
	DWORD                    dwRightId;  
	DWORD                    dwcOccurr;
//	float                    probability;                  // how often the character appears in the input block
	DWORD                    dwSequence;                   // bit signature for the character
	BYTE                     bySequLen;                    // length of the bit signature
} LHT_ITEM, *PLHT_ITEM;

//
// LiteralHuffTree class
//
class LiteralHuffTree
{
public:
	LiteralHuffTree(void);
	~LiteralHuffTree(void);

	DWORD      m_dwOccurr[256];

	BOOL       Generate( PBYTE buff, DWORD cb );
	BOOL       GenerateWithOccurrences();
	BOOL       GenerateAdaptiveModel();

	DWORD      Emit( BYTE* pBuff, DWORD cbBuff );
	DWORD      RipEmittedTree( PBYTE pby, DWORD cb );
	DWORD      QueryLiteralByBitSequence( PByteReader reader );
	PLHT_ITEM  operator[]( UINT index ) { return &m_tree[index]; };

private:
	LHT_ITEM   m_tree[(256 * 2) - 1];
	UINT       m_ucTreeItems;

	void       GetByteOccurrences( PBYTE pby, DWORD cb );
	void       BuildInternalTree();
	void       LinkTreeElements();
	void       GenerateBitSequences();
	DWORD      GetBitCountForOccurrence();
};

typedef LiteralHuffTree *PLiteralHuffTree;