www.pudn.com > LZ77code.zip > main.cpp

#include  
#include  
#include  
 
#include "lz77.h" 
 
////////////////////////////////////////////////////////////////// 
// out file format: 
//		0;flag2;buffer;0;flag2;buffer;...flag1;flag2;bufferlast 
// flag1 - 2 bytes, source buffer block length 
//			if block size is 65536, be zero 
// flag2 - 2 bytes, compressed buffer length 
//			if can not compress, be same with flag1 
////////////////////////////////////////////////////////////////// 
 
 
void main(int argc, char* argv[]) 
{	 
	if (argc != 4) 
	{ 
		puts("Usage: "); 
		printf("    Compress : %s c sourcefile destfile\n", argv[0]); 
		printf("  Decompress : %s d sourcefile destfile\n", argv[0]); 
		return; 
	} 
 
	BYTE soubuf[65536]; 
	BYTE destbuf[65536 + 16]; 
 
	FILE* in; 
	FILE* out; 
	in = fopen(argv[2], "rb"); 
	if (in == NULL) 
	{ 
		puts("Can't open source file"); 
		return; 
	} 
	out = fopen(argv[3], "wb"); 
	if (out == NULL) 
	{ 
		puts("Can't open dest file"); 
		fclose(in); 
		return; 
	} 
	fseek(in, 0, SEEK_END); 
	long soulen = ftell(in); 
	fseek(in, 0, SEEK_SET); 
 
	CCompressLZ77 cc; 
	WORD flag1, flag2; 
	 
	if (argv[1][0] == 'c') // compress 
	{ 
		int last = soulen, act; 
		while ( last > 0 ) 
		{ 
			act = min(65536, last); 
			fread(soubuf, act, 1, in); 
			last -= act; 
			if (act == 65536)			// out 65536 bytes				 
				flag1 = 0;		 
			else					// out last blocks 
				flag1 = act; 
			fwrite(&flag1, sizeof(WORD), 1, out); 
 
			int destlen = cc.Compress((BYTE*)soubuf, act, (BYTE*)destbuf); 
			if (destlen == 0)		// can't compress the block 
			{ 
				flag2 = flag1; 
				fwrite(&flag2, sizeof(WORD), 1, out); 
				fwrite(soubuf, act, 1, out); 
			} 
			else 
			{ 
				flag2 = (WORD)destlen; 
				fwrite(&flag2, sizeof(WORD), 1, out);				 
				fwrite(destbuf, destlen, 1, out);				 
			} 
		} 
	} 
	else if (argv[1][0] == 'd') // decompress 
	{ 
		int last = soulen, act; 
		while (last > 0) 
		{ 
			fread(&flag1, sizeof(WORD), 1, in); 
			fread(&flag2, sizeof(WORD), 1, in); 
			last -= 2 * sizeof(WORD); 
			if (flag1 == 0) 
				act = 65536; 
			else 
				act = flag1; 
			last-= flag2 ? (flag2) : act; 
 
			if (flag2 == flag1) 
			{ 
				fread(soubuf, act, 1, in);				 
			} 
			else 
			{ 
				fread(destbuf, flag2, 1, in); 
				if (!cc.Decompress((BYTE*)soubuf, act, (BYTE*)destbuf)) 
				{ 
					puts("Decompress error"); 
					fclose(in); 
					fclose(out); 
					return; 
				} 
			} 
			fwrite((BYTE*)soubuf, act, 1, out);				 
		} 
	} 
	else 
	{ 
		puts("Usage: "); 
		printf("    Compress : %s c sourcefile destfile\n", argv[0]); 
		printf("  Decompress : %s d sourcefile destfile\n", argv[0]);		 
	} 
 
	fclose(in); 
	fclose(out); 
}