bitio.cpp

使用半适应的huffman算法实现了文件的压缩和解压

#include "bitio.h"

bitFile::bitFile(const char* filepath){
	mask = 1;
	fopen_s(&fp,filepath,"r+b");
}

bitFile::~bitFile(){
	fclose(fp);
}

void bitFile::putBlock(unsigned char* value,int count){
	fwrite(value,sizeof(char),count,fp);
}

int bitFile::getBlock(unsigned char* value){
	return fread(value,sizeof(char),100,fp);
}

void bitFile::writeChar(int value){
	fputc(value,fp);
}

int bitFile::getChar(void){
	return fgetc(fp);
}

void bitFile::reInstall(void){
	fseek(fp,0,0);
}

void bitFile::toTail(void){
	fseek(fp,0,2);
}

int bitFile::getBit(void){
	int mk;
	int rt;

	mk = maskNext();
	if(mk == 128){
		rt = fread(& ibuffer,sizeof(char),1,fp);
		if(rt == 0)
			return -1;
	}
	if((ibuffer & mk) != 0)
		return 1;
	return 0;
}

int bitFile::maskNext(void){
	int mk;
	mk = mask;

	switch(mask){
		case 128: mask = 64; break;
		case 64: mask = 32; break;
		case 32: mask = 16; break;
		case 16: mask = 8; break;
		case 8: mask = 4; break;
		case 4: mask = 2; break;
		case 2: mask = 1; break;
		case 1: mask = 128; break;
	}
	return mk;
}