jerasure/Examples/cauchy_01.c

84 lines
3.1 KiB
C

/* *
* Copyright (c) 2013, James S. Plank and Kevin Greenan
* All rights reserved.
*
* Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure
* Coding Techniques
*
* Revision 2.0: Galois Field backend now links to GF-Complete
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* - Neither the name of the University of Tennessee nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "jerasure.h"
#include "reed_sol.h"
#define talloc(type, num) (type *) malloc(sizeof(type)*(num))
usage(char *s)
{
fprintf(stderr, "usage: cauchy_01 n w - Prints the number of ones in the bitmatrix representation of n in GF(2^w).\n");
fprintf(stderr, " \n");
fprintf(stderr, " It also prints out the bit-matrix and confirms that the number of ones is correct.\n");
fprintf(stderr, " \n");
fprintf(stderr, "This demonstrates: cauchy_n_ones()\n");
fprintf(stderr, " jerasure_matrix_to_bitmatrix()\n");
fprintf(stderr, " jerasure_print_bitmatrix()\n");
if (s != NULL) fprintf(stderr, "%s\n", s);
exit(1);
}
int main(int argc, char **argv)
{
int n, i, no, w;
int *bitmatrix;
if (argc != 3) usage(NULL);
if (sscanf(argv[1], "%d", &n) == 0 || n <= 0) usage("Bad n");
if (sscanf(argv[2], "%d", &w) == 0 || w <= 0 || w > 32) usage("Bad w");
if (w < 30 && n >= (1 << w)) usage("n is too big");
bitmatrix = jerasure_matrix_to_bitmatrix(1, 1, w, &n);
no = 0;
for (i = 0; i < w*w; i++) no += bitmatrix[i];
printf("# Ones: %d\n", cauchy_n_ones(n, w));
printf("\n");
printf("Bitmatrix has %d ones\n", no);
printf("\n");
jerasure_print_bitmatrix(bitmatrix, w, w, w);
return 0;
}