1 files changed, 118 insertions, 0 deletions
diff --git a/src/erasure-code/jerasure/jerasure/Examples/jerasure_04.c b/src/erasure-code/jerasure/jerasure/Examples/jerasure_04.c
new file mode 100644
index 000000000..e550e3ff1
--- /dev/null
+++ b/src/erasure-code/jerasure/jerasure/Examples/jerasure_04.c
@@ -0,0 +1,118 @@
+/* *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "jerasure.h"
+
+#define talloc(type, num) (type *) malloc(sizeof(type)*(num))
+
+usage(char *s)
+{
+  fprintf(stderr, "usage: jerasure_04 k w - Performs the analogous bit-matrix operations to jerasure_03.\n\n");
+  fprintf(stderr, "       It converts the matrix to a kw*kw bit matrix and does the same operations.\n");
+  fprintf(stderr, "       k must be < 2^w.\n");
+  fprintf(stderr, "This demonstrates: jerasure_print_bitmatrix()\n");
+  fprintf(stderr, "                   jerasure_matrix_to_bitmatrix()\n");
+  fprintf(stderr, "                   jerasure_invertible_bitmatrix()\n");
+  fprintf(stderr, "                   jerasure_invert_bitmatrix()\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 *bitmatrix;
+  int *bitmatrix_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);
+  bitmatrix_copy = talloc(int, k*w*k*w);
+  inverse = talloc(int, k*w*k*w);
+
+  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);
+    }
+  }
+  bitmatrix = jerasure_matrix_to_bitmatrix(k, k, w, matrix);
+
+  printf("<HTML><TITLE>jerasure_04");
+  for (i = 1; i < argc; i++) printf(" %s", argv[i]);
+  printf("</TITLE>\n");
+  printf("<h3>jerasure_04");
+  for (i = 1; i < argc; i++) printf(" %s", argv[i]);
+  printf("</h3>\n");
+  printf("<pre>\n");
+
+  printf("The Cauchy Bit-Matrix:\n");
+  jerasure_print_bitmatrix(bitmatrix, k*w, k*w, w);
+  memcpy(bitmatrix_copy, bitmatrix, sizeof(int)*k*w*k*w);
+  i = jerasure_invertible_bitmatrix(bitmatrix_copy, k*w);
+  printf("\nInvertible: %s\n", (i == 1) ? "Yes" : "No");
+  if (i == 1) {
+    printf("\nInverse:\n");
+    memcpy(bitmatrix_copy, bitmatrix, sizeof(int)*k*w*k*w);
+    i = jerasure_invert_bitmatrix(bitmatrix_copy, inverse, k*w);
+    jerasure_print_bitmatrix(inverse, k*w, k*w, w);
+    identity = jerasure_matrix_multiply(inverse, bitmatrix, k*w, k*w, k*w, k*w, 2);
+    printf("\nInverse times matrix (should be identity):\n");
+    jerasure_print_bitmatrix(identity, k*w, k*w, w);
+  }
+  return 0;
+}
+