jerasure/Examples/jerasure_06.c

214 lines
6.9 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.
*/
/*
revised by S. Simmerman
2/25/08
*/
#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_06 k m w packetsize\n");
fprintf(stderr, "Does a simple Cauchy Reed-Solomon coding example in GF(2^w).\n");
fprintf(stderr, " \n");
fprintf(stderr, " k+m must be < 2^w. Packetsize must be a multiple of sizeof(long)\n");
fprintf(stderr, " It sets up a Cauchy distribution matrix and encodes k devices of w*packetsize bytes.\n");
fprintf(stderr, " After that, it decodes device 0 by using jerasure_make_decoding_bitmatrix()\n");
fprintf(stderr, " and jerasure_bitmatrix_dotprod().\n");
fprintf(stderr, " \n");
fprintf(stderr, "This demonstrates: jerasure_bitmatrix_encode()\n");
fprintf(stderr, " jerasure_bitmatrix_decode()\n");
fprintf(stderr, " jerasure_print_bitmatrix()\n");
fprintf(stderr, " jerasure_make_decoding_bitmatrix()\n");
fprintf(stderr, " jerasure_bitmatrix_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 psize,
char **data, char **coding)
{
int i, j, x, n, sp;
long l;
if(k > m) n = k;
else n = m;
sp = psize * 2 + (psize/4) + 12;
printf("%-*sCoding\n", sp, "Data");
for(i = 0; i < n; i++) {
for (j = 0; j < w; j++) {
if(i < k) {
if(j==0) printf("D%-2d p%-2d:", i,j);
else printf(" p%-2d:", j);
for(x = 0; x < psize; x +=4) {
memcpy(&l, data[i]+j*psize+x, sizeof(long));
printf(" %08lx", l);
}
printf(" ");
}
else printf("%*s", sp, "");
if(i < m) {
if(j==0) printf("C%-2d p%-2d:", i,j);
else printf(" p%-2d:", j);
for(x = 0; x < psize; x +=4) {
memcpy(&l, coding[i]+j*psize+x, sizeof(long));
printf(" %08lx", l);
}
}
printf("\n");
}
}
printf("\n");
}
int main(int argc, char **argv)
{
long l;
int k, w, i, j, m, psize, x;
int *matrix, *bitmatrix;
char **data, **coding;
int *erasures, *erased;
int *decoding_matrix, *dm_ids;
if (argc != 5) 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 <= 0 || w > 32) usage("Bad w");
if (w < 30 && (k+m) > (1 << w)) usage("k + m is too big");
if (sscanf(argv[4], "%d", &psize) == 0 || psize <= 0) usage("Bad packetsize");
if(psize%sizeof(long) != 0) usage("Packetsize must be multiple of sizeof(long)");
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);
}
}
bitmatrix = jerasure_matrix_to_bitmatrix(k, m, w, matrix);
printf("Last (m * w) rows of the Binary Distribution Matrix:\n\n");
jerasure_print_bitmatrix(bitmatrix, w*m, w*k, w);
printf("\n");
srand48(0);
data = talloc(char *, k);
for (i = 0; i < k; i++) {
data[i] = talloc(char, psize*w);
for (j = 0; j < w; j++) {
for(x = 0; x < psize; x += 4) {
l = lrand48();
memcpy(data[i]+j*psize+x, &l, sizeof(long));
}
}
}
coding = talloc(char *, m);
for (i = 0; i < m; i++) {
coding[i] = talloc(char, psize*w);
}
jerasure_bitmatrix_encode(k, m, w, bitmatrix, data, coding, w*psize, psize);
printf("Encoding Complete:\n\n");
print_data_and_coding(k, m, w, psize, 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] = lrand48()%(k+m);
if (erased[erasures[i]] == 0) {
erased[erasures[i]] = 1;
bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], psize*w);
i++;
}
}
erasures[i] = -1;
printf("Erased %d random devices:\n\n", m);
print_data_and_coding(k, m, w, psize, data, coding);
i = jerasure_bitmatrix_decode(k, m, w, bitmatrix, 0, erasures, data, coding,
w*psize, psize);
printf("State of the system after decoding:\n\n");
print_data_and_coding(k, m, w, psize, data, coding);
decoding_matrix = talloc(int, k*k*w*w);
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_bitmatrix(k, m, w, bitmatrix, erased, decoding_matrix, dm_ids);
printf("Suppose we erase the first %d devices. Here is the decoding matrix:\n\n", m);
jerasure_print_bitmatrix(decoding_matrix, k*w, k*w, w);
printf("\n");
printf("And dm_ids:\n\n");
jerasure_print_matrix(dm_ids, 1, k, w);
//memcpy(&l, data[0], sizeof(long));
//printf("\nThe value of device #%d, word 0 is: %lx\n", 0, l);
bzero(data[0], w*psize);
jerasure_bitmatrix_dotprod(k, w, decoding_matrix, dm_ids, 0, data, coding, w*psize, psize);
printf("\nAfter calling jerasure_matrix_dotprod, we calculate the value of device #0, packet 0 to be:\n");
printf("\nD0 p0 :");
for(i = 0; i < psize; i +=sizeof(long)) {
memcpy(&l, data[0]+i, sizeof(long));
printf(" %08lx", l);
}
printf("\n\n");
//memcpy(&l, data[0], sizeof(long));
return 0;
}