www.pudn.com > lzari_SRC.rar > lzari.h

 
/************************************************************** 
	LZARI.C -- A Data Compression Program 
	(tab = 4 spaces) 
*************************************************************** 
	4/7/1989 Haruhiko Okumura 
	Use, distribute, and modify this program freely. 
	Please send me your improved versions. 
		PC-VAN		SCIENCE 
		NIFTY-Serve	PAF01022 
		CompuServe	74050,1022 
**************************************************************/ 
 
/********** Bit I/O **********/ 
#ifndef _FILE_H_COMPRESSION_LZARI_ 
#define  _FILE_H_COMPRESSION_LZARI_ 
//#pragma warning(disable:4786) 
//#include  
 
#define _OUTPUT_STATUS 
 
#define N		 4096	/* size of ring buffer */ 
#define F		   60	/* upper limit for match_length */ 
#define THRESHOLD	2   /* encode string into position and length 
						   if match_length is greater than this */ 
#define NIL			N	/* index for root of binary search trees */ 
/********** Arithmetic Compression **********/ 
 
/*  If you are not familiar with arithmetic compression, you should read 
		I. E. Witten, R. M. Neal, and J. G. Cleary, 
			Communications of the ACM, Vol. 30, pp. 520-540 (1987), 
	from which much have been borrowed.  */ 
 
#define M   15 
 
/*	Q1 (= 2 to the M) must be sufficiently large, but not so 
	large as the unsigned long 4 * Q1 * (Q1 - 1) overflows.  */ 
 
#define Q1  (1UL << M) 
#define Q2  (2 * Q1) 
#define Q3  (3 * Q1) 
#define Q4  (4 * Q1) 
#define MAX_CUM (Q1 - 1) 
 
#define N_CHAR  (256 - THRESHOLD + F) 
 
class LZARI  
{ 
public:	 
	LZARI(); 
	virtual ~LZARI(); 
protected: 
	FILE  *infile, *outfile; 
	unsigned long textsize; 
	unsigned long codesize; 
	unsigned long printcount; 
	unsigned char  text_buf[N + F - 1];	/* ring buffer of size N,with extra F-1 bytes to facilitate string comparison */ 
	int	match_position; 
	int	match_length;  /* of longest match.  These areset by the InsertNode() procedure. */ 
	int	lson[N + 1]; 
	int rson[N + 257]; 
	int dad[N + 1];  /* left & right children &parents -- These constitute binary search trees. */ 
 
	/* character code = 0, 1, ..., N_CHAR - 1 */ 
 
	unsigned long low; 
	unsigned long high; 
	unsigned long value; 
	int  shifts;  /* counts for magnifying low and high around Q2 */ 
	int  char_to_sym[N_CHAR]; 
	int sym_to_char[N_CHAR + 1]; 
	unsigned int sym_freq[N_CHAR + 1];  /* frequency for symbols */ 
	unsigned int sym_cum[N_CHAR + 1];   /* cumulative freq for symbols */ 
	unsigned int position_cum[N + 1];   /* cumulative freq for positions */ 
 
	// Compress in memory; 
	bool m_bMem; 
 
	std::vector m_OutBuffer; 
	//BYTE *m_pOutBuffer; 
	int m_nOutLength; 
	//int m_nOutCur; 
 
	const BYTE *m_pInBuffer; 
	int m_nInLength; 
	int m_nInCur; 
 
	unsigned int  buffer_putbit, mask_putbit; 
	unsigned int  buffer_getbit, mask_getbit; 
 
private: 
	void Error(char *message); 
	void PutBit(int bit);  /* Output one bit (bit = 0,1) */ 
	void FlushBitBuffer(void);  /* Send remaining bits */ 
	int GetBit(void);  /* Get one bit (0 or 1) */ 
 
/********** LZSS with multiple binary trees **********/ 
 
	void InitTree(void);  /* Initialize trees */ 
	void InsertNode(int r); 
	void DeleteNode(int p);  /* Delete node p from tree */ 
	void StartModel(void); /* Initialize model */ 
	void UpdateModel(int sym); 
	void Output(int bit);  /* Output 1 bit, followed by its complements */ 
	void EncodeChar(int ch); 
	void EncodePosition(int position); 
	void EncodeEnd(void); 
	int BinarySearchSym(unsigned int x); 
	int BinarySearchPos(unsigned int x); 
	void StartDecode(void); 
	int DecodeChar(void); 
	int DecodePosition(void); 
 
	void Encode(void); 
	void Decode(void); 
 
public: 
	void Compress(const char *lpszInfile,const char *lpszOutfile); 
	void UnCompress(const char *lpszInfile,const char *lpszOutfile); 
 
	void Compress(const BYTE *pInBuffer,int nInLength,const BYTE * &pOutBuffer ,int &nOutLength); 
	void UnCompress(const BYTE *pInBuffer,int nInLength,const BYTE * &pOutBuffer,int &nOutLength); 
	 
	void Release(); 
}; 
 
#endif