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/* *
* 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 <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <gf_rand.h>
#include "jerasure.h"
#define talloc(type, num) (type *) malloc(sizeof(type)*(num))
static void usage(char *s)
{
fprintf(stderr, "usage: jerasure_05 k m w size seed - Does a simple Reed-Solomon coding example in GF(2^w).\n");
fprintf(stderr, " \n");
fprintf(stderr, " k+m must be <= 2^w. w can be 8, 16 or 32.\n");
fprintf(stderr, " It sets up a Cauchy generator matrix and encodes\n");
fprintf(stderr, " k devices of size bytes with it. Then it decodes.\n");
fprintf(stderr, " After that, it decodes device 0 by using jerasure_make_decoding_matrix()\n");
fprintf(stderr, " and jerasure_matrix_dotprod().\n");
fprintf(stderr, " \n");
fprintf(stderr, "This demonstrates: jerasure_matrix_encode()\n");
fprintf(stderr, " jerasure_matrix_decode()\n");
fprintf(stderr, " jerasure_print_matrix()\n");
fprintf(stderr, " jerasure_make_decoding_matrix()\n");
fprintf(stderr, " jerasure_matrix_dotprod()\n");
if (s != NULL) fprintf(stderr, "\n%s\n\n", s);
exit(1);
}
static void print_data_and_coding(int k, int m, int w, int size,
char **data, char **coding)
{
int i, j, x;
int n, sp;
if(k > m) n = k;
else n = m;
sp = size * 2 + size/(w/8) + 8;
printf("%-*sCoding\n", sp, "Data");
for(i = 0; i < n; i++) {
if(i < k) {
printf("D%-2d:", i);
for(j=0;j< size; j+=(w/8)) {
printf(" ");
for(x=0;x < w/8;x++){
printf("%02x", (unsigned char)data[i][j+x]);
}
}
printf(" ");
}
else printf("%*s", sp, "");
if(i < m) {
printf("C%-2d:", i);
for(j=0;j< size; j+=(w/8)) {
printf(" ");
for(x=0;x < w/8;x++){
printf("%02x", (unsigned char)coding[i][j+x]);
}
}
}
printf("\n");
}
printf("\n");
}
int main(int argc, char **argv)
{
int k, m, w, size;
int i, j;
int *matrix;
char **data, **coding;
int *erasures, *erased;
int *decoding_matrix, *dm_ids;
uint32_t seed;
if (argc != 6) usage(NULL);
if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k");
if (sscanf(argv[2], "%d", &m) == 0 || m <= 0) usage("Bad m");
if (sscanf(argv[3], "%d", &w) == 0 || (w != 8 && w != 16 && w != 32)) usage("Bad w");
if (w < 32 && k + m > (1 << w)) usage("k + m must be <= 2 ^ w");
if (sscanf(argv[4], "%d", &size) == 0 || size % sizeof(long) != 0)
usage("size must be multiple of sizeof(long)");
if (sscanf(argv[5], "%d", &seed) == 0) usage("Bad seed");
matrix = talloc(int, m*k);
for (i = 0; i < m; i++) {
for (j = 0; j < k; j++) {
matrix[i*k+j] = galois_single_divide(1, i ^ (m + j), w);
}
}
printf("<HTML><TITLE>jerasure_05");
for (i = 1; i < argc; i++) printf(" %s", argv[i]);
printf("</TITLE>\n");
printf("<h3>jerasure_05");
for (i = 1; i < argc; i++) printf(" %s", argv[i]);
printf("</h3>\n");
printf("<pre>\n");
printf("The Coding Matrix (the last m rows of the Generator Matrix G^T):\n\n");
jerasure_print_matrix(matrix, m, k, w);
printf("\n");
MOA_Seed(seed);
data = talloc(char *, k);
for (i = 0; i < k; i++) {
data[i] = talloc(char, size);
MOA_Fill_Random_Region(data[i], size);
}
coding = talloc(char *, m);
for (i = 0; i < m; i++) {
coding[i] = talloc(char, size);
}
jerasure_matrix_encode(k, m, w, matrix, data, coding, size);
printf("Encoding Complete:\n\n");
print_data_and_coding(k, m, w, size, data, coding);
erasures = talloc(int, (m+1));
erased = talloc(int, (k+m));
for (i = 0; i < m+k; i++) erased[i] = 0;
for (i = 0; i < m; ) {
erasures[i] = (MOA_Random_W(w, 1))%(k+m);
if (erased[erasures[i]] == 0) {
erased[erasures[i]] = 1;
bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], size);
i++;
}
}
erasures[i] = -1;
printf("Erased %d random devices:\n\n", m);
print_data_and_coding(k, m, w, size, data, coding);
i = jerasure_matrix_decode(k, m, w, matrix, 0, erasures, data, coding, size);
printf("State of the system after decoding:\n\n");
print_data_and_coding(k, m, w, size, data, coding);
decoding_matrix = talloc(int, k*k);
dm_ids = talloc(int, k);
for (i = 0; i < m; i++) erased[i] = 1;
for (; i < k+m; i++) erased[i] = 0;
jerasure_make_decoding_matrix(k, m, w, matrix, erased, decoding_matrix, dm_ids);
printf("Suppose we erase the first %d devices. Here is the decoding matrix:\n\n", m);
jerasure_print_matrix(decoding_matrix, k, k, w);
printf("\n");
printf("And dm_ids:\n\n");
jerasure_print_matrix(dm_ids, 1, k, w);
bzero(data[0], size);
jerasure_matrix_dotprod(k, w, decoding_matrix, dm_ids, 0, data, coding, size);
printf("\nAfter calling jerasure_matrix_dotprod, we calculate the value of device #0 to be:\n\n");
printf("D0 :");
for(i=0;i< size; i+=(w/8)) {
printf(" ");
for(j=0;j < w/8;j++){
printf("%02x", (unsigned char)data[0][i+j]);
}
}
printf("\n\n");
return 0;
}
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