220 lines
6.8 KiB
C
220 lines
6.8 KiB
C
/* *
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* Copyright (c) 2013, James S. Plank and Kevin Greenan
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* All rights reserved.
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*
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* Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure
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* Coding Techniques
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*
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* Revision 2.0: Galois Field backend now links to GF-Complete
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* - Neither the name of the University of Tennessee nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
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* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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revised by S. Simmerman
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2/25/08
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*/
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <gf_rand.h>
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#include "jerasure.h"
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#define talloc(type, num) (type *) malloc(sizeof(type)*(num))
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usage(char *s)
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{
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fprintf(stderr, "usage: jerasure_05 k m w size seed - Does a simple Reed-Solomon coding example in GF(2^w).\n");
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fprintf(stderr, " \n");
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fprintf(stderr, " k+m must be <= 2^w. w can be 8, 16 or 32.\n");
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fprintf(stderr, " It sets up a Cauchy generator matrix and encodes\n");
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fprintf(stderr, " k devices of size bytes with it. Then it decodes.\n");
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fprintf(stderr, " After that, it decodes device 0 by using jerasure_make_decoding_matrix()\n");
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fprintf(stderr, " and jerasure_matrix_dotprod().\n");
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fprintf(stderr, " \n");
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fprintf(stderr, "This demonstrates: jerasure_matrix_encode()\n");
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fprintf(stderr, " jerasure_matrix_decode()\n");
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fprintf(stderr, " jerasure_print_matrix()\n");
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fprintf(stderr, " jerasure_make_decoding_matrix()\n");
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fprintf(stderr, " jerasure_matrix_dotprod()\n");
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if (s != NULL) fprintf(stderr, "\n%s\n\n", s);
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exit(1);
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}
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static void print_data_and_coding(int k, int m, int w, int size,
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char **data, char **coding)
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{
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int i, j, x;
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int n, sp;
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long l;
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if(k > m) n = k;
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else n = m;
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sp = size * 2 + size/(w/8) + 8;
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printf("%-*sCoding\n", sp, "Data");
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for(i = 0; i < n; i++) {
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if(i < k) {
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printf("D%-2d:", i);
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for(j=0;j< size; j+=(w/8)) {
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printf(" ");
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for(x=0;x < w/8;x++){
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printf("%02x", (unsigned char)data[i][j+x]);
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}
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}
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printf(" ");
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}
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else printf("%*s", sp, "");
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if(i < m) {
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printf("C%-2d:", i);
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for(j=0;j< size; j+=(w/8)) {
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printf(" ");
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for(x=0;x < w/8;x++){
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printf("%02x", (unsigned char)coding[i][j+x]);
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}
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}
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}
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printf("\n");
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}
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printf("\n");
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}
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int main(int argc, char **argv)
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{
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long l;
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int k, m, w, size;
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int i, j;
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int *matrix;
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char **data, **coding;
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int *erasures, *erased;
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int *decoding_matrix, *dm_ids;
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uint32_t seed;
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if (argc != 6) usage(NULL);
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if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k");
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if (sscanf(argv[2], "%d", &m) == 0 || m <= 0) usage("Bad m");
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if (sscanf(argv[3], "%d", &w) == 0 || (w != 8 && w != 16 && w != 32)) usage("Bad w");
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if (w < 32 && k + m > (1 << w)) usage("k + m must be <= 2 ^ w");
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if (sscanf(argv[4], "%d", &size) == 0 || size % sizeof(long) != 0)
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usage("size must be multiple of sizeof(long)");
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if (sscanf(argv[5], "%d", &seed) == 0) usage("Bad seed");
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matrix = talloc(int, m*k);
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for (i = 0; i < m; i++) {
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for (j = 0; j < k; j++) {
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matrix[i*k+j] = galois_single_divide(1, i ^ (m + j), w);
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}
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}
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printf("<HTML><TITLE>jerasure_05");
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for (i = 1; i < argc; i++) printf(" %s", argv[i]);
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printf("</TITLE>\n");
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printf("<h3>jerasure_05");
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for (i = 1; i < argc; i++) printf(" %s", argv[i]);
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printf("</h3>\n");
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printf("<pre>\n");
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printf("The Coding Matrix (the last m rows of the Generator Matrix G^T):\n\n");
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jerasure_print_matrix(matrix, m, k, w);
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printf("\n");
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MOA_Seed(seed);
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data = talloc(char *, k);
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for (i = 0; i < k; i++) {
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data[i] = talloc(char, size);
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MOA_Fill_Random_Region(data[i], size);
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}
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coding = talloc(char *, m);
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for (i = 0; i < m; i++) {
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coding[i] = talloc(char, size);
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}
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jerasure_matrix_encode(k, m, w, matrix, data, coding, size);
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printf("Encoding Complete:\n\n");
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print_data_and_coding(k, m, w, size, data, coding);
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erasures = talloc(int, (m+1));
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erased = talloc(int, (k+m));
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for (i = 0; i < m+k; i++) erased[i] = 0;
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l = 0;
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for (i = 0; i < m; ) {
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erasures[i] = (MOA_Random_W(w, 1))%(k+m);
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if (erased[erasures[i]] == 0) {
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erased[erasures[i]] = 1;
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bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], size);
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i++;
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}
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}
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erasures[i] = -1;
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printf("Erased %d random devices:\n\n", m);
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print_data_and_coding(k, m, w, size, data, coding);
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i = jerasure_matrix_decode(k, m, w, matrix, 0, erasures, data, coding, size);
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printf("State of the system after decoding:\n\n");
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print_data_and_coding(k, m, w, size, data, coding);
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decoding_matrix = talloc(int, k*k);
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dm_ids = talloc(int, k);
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for (i = 0; i < m; i++) erased[i] = 1;
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for (; i < k+m; i++) erased[i] = 0;
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jerasure_make_decoding_matrix(k, m, w, matrix, erased, decoding_matrix, dm_ids);
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printf("Suppose we erase the first %d devices. Here is the decoding matrix:\n\n", m);
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jerasure_print_matrix(decoding_matrix, k, k, w);
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printf("\n");
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printf("And dm_ids:\n\n");
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jerasure_print_matrix(dm_ids, 1, k, w);
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bzero(data[0], size);
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jerasure_matrix_dotprod(k, w, decoding_matrix, dm_ids, 0, data, coding, size);
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printf("\nAfter calling jerasure_matrix_dotprod, we calculate the value of device #0 to be:\n\n");
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printf("D0 :");
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for(i=0;i< size; i+=(w/8)) {
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printf(" ");
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for(j=0;j < w/8;j++){
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printf("%02x", (unsigned char)data[0][i+j]);
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}
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}
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printf("\n\n");
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return 0;
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}
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