unslz

#include <iostream>#include <fstream>#include <cstdlib>#include <string.h>using namespace std;extern fstream out;extern fstream in;ifstream inputfile;ifstream::pos_type file_position;struct slz{  int signature;			// "SLZ*" * - rozne wartosci  int data_size;			// total data size (-header)  int unpacked_size;		// unpack size  int offset;				// next file offset (or total current file size)} __attribute__ ((__packed__));intslz_triace_blah (int x, int n, int a, unsigned char **o, unsigned char *outl){  unsigned char *    t = *o;  printf (" slz_triace_blah; x = %x n = %x a = %x \n", x, n, a);  if (x < n)    {      printf (" x<n \n");      n = (((n - x) - 1) >> 1) + 1;      x += n * 2;      printf (" .. slz_triace x %X n %X a %X\n", x, n, a);      if ((t + (n * 2)) > outl)	return (-1);      printf (" .. slz_triace ->> ");      while (n--)	{	  *t++ = a;	  *t++ = a >> 8;	  printf (" .. slz_triace %X %X", a, a >> 8);	}      printf ("\n");      *o = t;    }  return (x);}int	slzDecompress (	unsigned char *bufferin,					unsigned char *bufferout,					unsigned int insize, 					unsigned int outsize, 					int type){  unsigned char * src = bufferin;  unsigned char * dst = bufferout;  cout << "preparation" << endl;  int flag, n, x, a;  for (flag = 0; dst < bufferout + outsize; flag >>= 1) {      printf (" -- at position %x \n", dst - bufferout);      if (!(flag & 0xff00))	{		cout << " -- reading the control byte" << endl;		if (src >= bufferin + insize)			break;		flag = 0xff00 | *src++;		printf (" -- we have %2X as a control byte \n ", (unsigned int)(flag & 0xFF));		}				if (flag & 1) {			//bit = 1			printf( " -- current bit is 1 - copying 1 byte of input \n");		if (src >= bufferin + insize)			break;		//za malo danych, potrzebny chociaz 1 bajt		if (dst >= bufferout + outsize)			return (-1);	//za duzo danych wygenerowane		printf(" copy: copying %X to output \n", (unsigned int) (*src));		*dst++ = *src++;	//kopiujemy 1 bajt i do przodu	} else { //bit = 0 - lzss	  cout << " -- 0 bit found; doing the lzss " << endl;	  if (src + 2 > bufferin + insize)	    break;		//do we have 2 more bytes of input?	  n = *src++;			//grab 1 byte and go forth	  n |= (*src++ << 8);	//grab another byte and put it "over" the previous byte	  x = ((n >> 12) & 0x0f) + 3;	//x - howMany , n - offset	  n &= 0x0fff;					//we only need the lower 12 bits of n	  printf (" lzss : n = %x x = %x \n", n, x);	  if ((x < 0x12) || (type != 2))	    {	      printf( " lzss : x< 0x12 or compression type != 2 \n");	      if ((dst - n) < bufferout)	//we cannot reference before the beginning of the data			return (-1);		      if ((dst + x) > bufferout + outsize)	//if we have more bytes than the output can hold			return (-1);	//we bail out	      printf ("  lzss: copy %X bytes from position %X in output ", x,		      (unsigned int) (dst - bufferin - n));	      while (x--) {			printf (" %X ", (unsigned int) *(dst - n));			*dst = *(dst - n);	//we copy a byte from n bytes earlier			dst++;	//we do so x times			}	      printf ("\n");	    }	  else {	      cout << " lzss : x >= 0x12 and type = 2 " << endl;	      if (n < 0x100)	{			cout << "  lzss: n < 0x100" << endl;			if (src >= bufferin + insize)  //if there is no more input			      break;						//bail			a = *src++;			n += 0x13;			printf (" . lzss : x %x n %x a %x \n", x, n, a);		} else {			cout << "  lzss : n>= 0x100" << endl;			a = n & 0xff;			n = (((n >> 8) & 0xf) + 3);			printf (" lzss: x %x n %x a %x \n", x, n, a);		}		// n< -0x100	    a |= (a << 8);	    if ((dst - bufferout) & 1)	{		//odd amount of bytes left?			if (dst > bufferout + outsize)	//are we past last byte?				return (-1);			printf ("  copying %X to output \n", a);			*dst++ = a;			if (n & 1)	{		      printf ("  lzss : n &1 \n");		      printf ("  lzss : doing n = ((n - 2) >> 1) + 1; \n");		      n = ((n - 2) >> 1) + 1;		      printf ("  lzss : n = %x \n", n);		      if ((dst + (n * 2)) > bufferout + outsize)				return (-1);	//can we fit n*2 bytes?		      printf ("  lzss: copy %x bytes from %X \n", n, a);		      while (n--)	{				printf (" %X ", (unsigned int) a);				*dst++ = a;				*dst++ = a >> 8;				}		      printf (" copied \n");		    }		  else if ((n - 1) > 1)	{			  printf ("  (n - 1) >1 \n");						      x =slz_triace_blah (1, n - 1, a, &dst, bufferout + outsize);		      if (x < 0)				return (-1);		      if (x < n) {				if (dst >= bufferout + outsize)					return (-1);				*dst++ = a;				}		    }		  else if (n > 1) {			  if (dst >= bufferout + outsize)				return (-1);				*dst++ = a;		    } else {			  x = slz_triace_blah (0, n - 1, a, &dst, bufferout + outsize);		      if (x < 0)				return (-1);		      if (x < n) {				if (dst >= bufferout + outsize)					return (-1);				*dst++ = a;				}			}		} else {			printf(" x %X n %X a %X \n", x,n,a);			printf( "  .. slz_triace_blah(0, n - 1, a, &dst, dst+outsize) \n");			x = slz_triace_blah(0, n - 1, a, &dst, dst+outsize);			printf("  . x %X n %X a %X \n", x,n,a);			printf("  is x > 0 ? \n");			if(x < 0) 				return(-1);			printf("  is x < n ?\n");            if(x < n) {				if(dst >= dst+outsize) 					return(-1);				printf("  copying %X to output \n" , a);                *dst++ = a;            }          }					    }	}    }  return (dst - bufferout);	//did we finish?}boolverify_header (ifstream & input){  cout << "  verify header" << endl;  slz    naglowek;  memset (&naglowek, 0, sizeof (naglowek));  input.read (reinterpret_cast < char *>(&naglowek), sizeof (naglowek));  printf ("    signature %x \n", naglowek.signature & 0x00FFFFFF);  printf ("    flag      %x \n", naglowek.signature >> 24);  printf ("    unpacked  %x \n", naglowek.unpacked_size);  printf ("    offset    %x \n", naglowek.offset);  char *    tmp = reinterpret_cast < char *>(&naglowek.signature);  char    type[4];  strncpy (type, tmp, sizeof (type) - 1);  type[sizeof (type) - 1] = '\0';  printf ("  so we have %s file with compression %d \n", type,	  naglowek.signature >> 24);  char *    data;  char *    data_out;  data = new char[naglowek.data_size];  data_out = new char[naglowek.unpacked_size];  memset (data, 0, sizeof (data));  memset (data_out, 0, sizeof (data_out));  input.seekg (0x10, ios::beg);  input.read (data, naglowek.data_size);  cout << "unpack" << endl;  if (!(slzDecompress ((unsigned char *) data, (unsigned char *) data_out, naglowek.data_size, naglowek.unpacked_size, naglowek.signature >> 24)))	//naglowek.unpacked_size);    cout << " unpack ok " << endl;  ofstream    output;  output.open ("output.dat");  if (output.is_open ())    {      output.write (data_out, naglowek.unpacked_size);	//sizeof (&data_out));      output.close ();      printf ("wrote output file\n");    }  return true;}intmain (int argc, char *argv[]){  if (!(argc == 2))    {      cout << "specify one input file" << endl;    }  inputfile.open (argv[1], ios::in | ios::binary);  if (!inputfile.is_open ())    {      cout << "failed to open file" << endl;      return 1;    }  cout << "file open" << endl;  file_position = 0;  inputfile.seekg (file_position, ios::beg);  if (verify_header (inputfile))    cout << " looks good" << endl;  inputfile.close ();  return 0;}