jerasure_03"); for (i = 1; i < argc; i++) printf(" %s", argv[i]); printf("

/* * * Copyright (c) 2014, 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. */ /* Jerasure's authors: Revision 2.x - 2014: James S. Plank and Kevin M. Greenan. Revision 1.2 - 2008: James S. Plank, Scott Simmerman and Catherine D. Schuman. Revision 1.0 - 2007: James S. Plank. */ #include #include #include #include "jerasure.h" #define talloc(type, num) (type *) malloc(sizeof(type)*(num)) static void usage(char *s) { fprintf(stderr, "usage: jerasure_03 k w - Creates a kxk Cauchy matrix in GF(2^w). \n\n"); fprintf(stderr, " k must be < 2^w. Element i,j is 1/(i+(2^w-j-1)). (If that is\n"); fprintf(stderr, " If that is 1/0, then it sets it to zero). \n"); fprintf(stderr, " It then tests whether that matrix is invertible.\n"); fprintf(stderr, " If it is invertible, then it prints out the inverse.\n"); fprintf(stderr, " Finally, it prints the product of the matrix and its inverse.\n"); fprintf(stderr, " \n"); fprintf(stderr, "This demonstrates: jerasure_print_matrix()\n"); fprintf(stderr, " jerasure_invertible_matrix()\n"); fprintf(stderr, " jerasure_invert_matrix()\n"); fprintf(stderr, " jerasure_matrix_multiply().\n"); if (s != NULL) fprintf(stderr, "%s\n", s); exit(1); } int main(int argc, char **argv) { unsigned int k, w, i, j, n; int *matrix; int *matrix_copy; int *inverse; int *identity; if (argc != 3) usage(NULL); if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k"); if (sscanf(argv[2], "%d", &w) == 0 || w <= 0 || w > 31) usage("Bad w"); if (k >= (1 << w)) usage("K too big"); matrix = talloc(int, k*k); matrix_copy = talloc(int, k*k); inverse = talloc(int, k*k); for (i = 0; i < k; i++) { for (j = 0; j < k; j++) { n = i ^ ((1 << w)-1-j); matrix[i*k+j] = (n == 0) ? 0 : galois_single_divide(1, n, w); } } printf("jerasure_03"); for (i = 1; i < argc; i++) printf(" %s", argv[i]); printf("\n"); printf("

jerasure_03"); for (i = 1; i < argc; i++) printf(" %s", argv[i]); printf("

\n"); printf("

\n");

  printf("The Cauchy Matrix:\n");
  jerasure_print_matrix(matrix, k, k, w);
  memcpy(matrix_copy, matrix, sizeof(int)*k*k);
  i = jerasure_invertible_matrix(matrix_copy, k, w);
  printf("\nInvertible: %s\n", (i == 1) ? "Yes" : "No");
  if (i == 1) {
    printf("\nInverse:\n");
    memcpy(matrix_copy, matrix, sizeof(int)*k*k);
    i = jerasure_invert_matrix(matrix_copy, inverse, k, w);
    jerasure_print_matrix(inverse, k, k, w);
    identity = jerasure_matrix_multiply(inverse, matrix, k, k, k, k, w);
    printf("\nInverse times matrix (should be identity):\n");
    jerasure_print_matrix(identity, k, k, w);
  }
  return 0;
}