LZW compression class definition and conception

#ifndef _LZW_H_INCLUDED
#define _LZW_H_INCLUDED
#include stdio.h // for getc, getwc
#include string.h // for memset
#include stdlib.h // for malloc, free

#define MAX_LZW_BITS 12 //Maximum LZW code size
#define LZW_TABLE_SIZE (1<#define HSIZE 5003 //Hash table 80% occupancy size

typedef int INT32;
typedef short UINT8;
typedef short code_int; //The value range is -1 to 2*MAX_LZE_BITS
typedef short hash_int; //The value range is -2 to 2*HSIZE

#define MAXCODE(n_bits) (((code_int)1<<(n_bits))-1)

class CLZW
{
public:
CLZW(); //Constructor
~ CLZW(); // Destructor

FILE* outfile;
FILE* infile;

int GetDataBlock(char *buf);//A zero-length block marks the end of the data block sequence
void SkipDataBlocks();//Find the end of the data block
void ReInitLZW();//Initialize LZW state
void InitLZWCode (FILE* file,int in_size);//Initialize the file object
int GetCode();//Extract the next code_size bits from the compressed data
int LzwReadByte();//Read a LZW compressed byte

void CHAR_OUT(int c);//Add a byte to the existing buffer
void flush_packet();//Clear the accumulated data in the buffer
void clear_hash();//Clear the hash table
void clear_block();//Reset compression and send a clear code
void output(code_int code);//Send a n_bits bit code and reassemble an 8-bit byte with cur_accum and cur_bits
void compress_init(FILE* file,int ibits);//Initialize LZW compression
void compress_byte(int c);//Compress an 8-bit byte
void compress_term();//Save the end

protected:
INT32 cur_accum;//Used to save bits that have not been output yet
int cur_bits;//bits in cur_accum
int n_bits;//Current bits/code number
code_int maxcode;//The largest code in n_bits
int code_counter;//Output symbol counter
int init_bits;//Initial n_bit..restore after clearing
code_int ClearCode;//Clear code (remain unchanged)
code_int EOFCode;//EOF code (end code)
bool first_byte;//Judge whether it is the first byte

//Compression
code_int free_code; //Alternate code
code_int *hash_code; //Symbol code Hash table
code_int *hash_prefix; //Prefix symbol Hash table
UINT8 *hash_suffix; //Suffix byte Hash table
code_int waiting_code; //Code not yet output
int bytesinpkt; //Number of bytes in the current buffer char packetbuf[256]; //Accumulation buffer
for compression

//Decompress
char code_buf[256+4]; //Current input data block
int last_byte; //Bytes in code_buf
int last_bit; //Bits in code_buf
bool out_of_blocks; //True value when the end is encountered
code_int *symbol_head; //Prefix symbol table
UINT8 *symbol_tail; //Suffix byte table
UINT8 *symbol_stack; //Stack for symbol expansion
UINT8 *sp; //Stack pointer

};

#endif