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Diffstat (limited to 'src/c/jerasure/Examples/reed_sol_01.c')
| -rw-r--r-- | src/c/jerasure/Examples/reed_sol_01.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/c/jerasure/Examples/reed_sol_01.c b/src/c/jerasure/Examples/reed_sol_01.c new file mode 100644 index 0000000..d50dda0 --- /dev/null +++ b/src/c/jerasure/Examples/reed_sol_01.c @@ -0,0 +1,195 @@ +/* * + * 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 <stdint.h> +#include <string.h> +#include <gf_rand.h> +#include "jerasure.h" +#include "reed_sol.h" + +#define talloc(type, num) (type *) malloc(sizeof(type)*(num)) + +static void usage(char *s) +{ + fprintf(stderr, "usage: reed_sol_01 k m w seed - Does a simple Reed-Solomon coding example in GF(2^w).\n"); + fprintf(stderr, " \n"); + fprintf(stderr, "w must be 8, 16 or 32. k+m must be <= 2^w. It sets up a classic\n"); + fprintf(stderr, "Vandermonde-based generator matrix and encodes k devices of\n"); + fprintf(stderr, "%ld bytes each with it. Then it decodes.\n", sizeof(long)); + 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, " reed_sol_vandermonde_coding_matrix()\n"); + if (s != NULL) fprintf(stderr, "%s\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) +{ + long l; + int k, w, i, j, m; + int *matrix; + char **data, **coding, **dcopy, **ccopy; + unsigned char uc; + int *erasures, *erased; + uint32_t seed; + + 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 != 8 && w != 16 && w != 32)) usage("Bad w"); + if (sscanf(argv[4], "%u", &seed) == 0) usage("Bad seed"); + if (w <= 16 && k + m > (1 << w)) usage("k + m is too big"); + + matrix = reed_sol_vandermonde_coding_matrix(k, m, w); + + printf("<HTML><TITLE>reed_sol_01 %d %d %d %d</title>\n", k, m, w, seed); + printf("<h3>reed_sol_01 %d %d %d %d</h3>\n", k, m, w, seed); + printf("<pre>\n"); + printf("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); + dcopy = talloc(char *, k); + for (i = 0; i < k; i++) { + data[i] = talloc(char, sizeof(long)); + dcopy[i] = talloc(char, sizeof(long)); + for (j = 0; j < sizeof(long); j++) { + uc = MOA_Random_W(8, 1); + data[i][j] = (char) uc; + } + memcpy(dcopy[i], data[i], sizeof(long)); + } + + coding = talloc(char *, m); + ccopy = talloc(char *, m); + for (i = 0; i < m; i++) { + coding[i] = talloc(char, sizeof(long)); + ccopy[i] = talloc(char, sizeof(long)); + } + + jerasure_matrix_encode(k, m, w, matrix, data, coding, sizeof(long)); + + for (i = 0; i < m; i++) { + memcpy(ccopy[i], coding[i], sizeof(long)); + } + + printf("Encoding Complete:\n\n"); + print_data_and_coding(k, m, w, sizeof(long), data, coding); + + erasures = talloc(int, (m+1)); + erased = talloc(int, (k+m)); + for (i = 0; i < m+k; i++) erased[i] = 0; + l = 0; + for (i = 0; i < m; ) { + erasures[i] = MOA_Random_W(31, 0)%(k+m); + if (erased[erasures[i]] == 0) { + erased[erasures[i]] = 1; + memcpy((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], &l, sizeof(long)); + i++; + } + } + erasures[i] = -1; + + printf("Erased %d random devices:\n\n", m); + print_data_and_coding(k, m, w, sizeof(long), data, coding); + + i = jerasure_matrix_decode(k, m, w, matrix, 1, erasures, data, coding, sizeof(long)); + + printf("State of the system after decoding:\n\n"); + print_data_and_coding(k, m, w, sizeof(long), data, coding); + + for (i = 0; i < k; i++) if (memcmp(data[i], dcopy[i], sizeof(long)) != 0) { + printf("ERROR: D%x after decoding does not match its state before decoding!<br>\n", i); + } + for (i = 0; i < m; i++) if (memcmp(coding[i], ccopy[i], sizeof(long)) != 0) { + printf("ERROR: C%x after decoding does not match its state before decoding!<br>\n", i); + } + + return 0; +} |