2 * Copyright (c) 2014, James S. Plank and Kevin Greenan
5 * Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure
8 * Revision 2.0: Galois Field backend now links to GF-Complete
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * - Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
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18 * notice, this list of conditions and the following disclaimer in
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22 * - Neither the name of the University of Tennessee nor the names of its
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26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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40 /* Jerasure's authors:
42 Revision 2.x - 2014: James S. Plank and Kevin M. Greenan
43 Revision 1.2 - 2008: James S. Plank, Scott Simmerman and Catherine D. Schuman.
44 Revision 1.0 - 2007: James S. Plank
55 #define talloc(type, num) (type *) malloc(sizeof(type)*(num))
57 static void usage(char *s)
59 fprintf(stderr, "usage: cauchy_02 k m w seed - CRS coding example using Bloemer's original matrix.\n");
60 fprintf(stderr, " \n");
61 fprintf(stderr, "k+m must be <= 2^w\n");
62 fprintf(stderr, "This sets up a generator matrix (G^T) in GF(2^w) whose last m rows are\n");
63 fprintf(stderr, "created from a Cauchy matrix, using the original definition from [Bloemer95].\n");
64 fprintf(stderr, "It converts this matrix to a bitmatrix, and then it encodes w packets from\n");
65 fprintf(stderr, "each of k disks (simulated) onto w packets on each of m disks. Packets are \n");
66 fprintf(stderr, "simply longs. Then, it deletes m random disks, and decodes. \n");
67 fprintf(stderr, "\n");
68 fprintf(stderr, "The encoding and decoding are done twice, first, with jerasure_bitmatrix_encode()\n");
69 fprintf(stderr, "and jerasure_bitmatrix_decode(), and second using 'smart' scheduling with\n");
70 fprintf(stderr, "jerasure_schedule_encode() and jerasure_schedule_decode_lazy().\n");
72 fprintf(stderr, "\n");
73 fprintf(stderr, "This demonstrates: cauchy_original_coding_matrix()\n");
74 fprintf(stderr, " jerasure_bitmatrix_encode()\n");
75 fprintf(stderr, " jerasure_bitmatrix_decode()\n");
76 fprintf(stderr, " cauchy_n_ones()\n");
77 fprintf(stderr, " jerasure_smart_bitmatrix_to_schedule()\n");
78 fprintf(stderr, " jerasure_schedule_encode()\n");
79 fprintf(stderr, " jerasure_schedule_decode_lazy()\n");
80 fprintf(stderr, " jerasure_print_matrix()\n");
81 fprintf(stderr, " jerasure_print_bitmatrix()\n");
82 fprintf(stderr, " jerasure_get_stats()\n");
83 if (s != NULL) fprintf(stderr, "%s\n", s);
87 static void print_array(char **ptrs, int ndevices, int size, int packetsize, char *label)
92 printf("<center><table border=3 cellpadding=3><tr><td></td>\n");
94 for (i = 0; i < ndevices; i++) printf("<td align=center>%s%x</td>\n", label, i);
96 printf("<td align=right><pre>");
97 for (j = 0; j < size/packetsize; j++) printf("Packet %d\n", j);
98 printf("</pre></td>\n");
99 for (i = 0; i < ndevices; i++) {
101 up = (unsigned char *) ptrs[i];
102 for (j = 0; j < size/packetsize; j++) {
103 for (x = 0; x < packetsize; x++) {
104 if (x > 0 && x%4 == 0) printf(" ");
105 printf("%02x", up[j*packetsize+x]);
111 printf("</tr></table></center>\n");
114 int main(int argc, char **argv)
117 int *matrix, *bitmatrix, **schedule;
118 char **data, **coding, **dcopy, **ccopy;
120 int *erasures, *erased;
121 double mstats[3], sstats[3];
124 if (argc != 5) usage(NULL);
125 if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k");
126 if (sscanf(argv[2], "%d", &m) == 0 || m <= 0) usage("Bad m");
127 if (sscanf(argv[3], "%d", &w) == 0 || w <= 0 || w > 32) usage("Bad w");
128 if (sscanf(argv[4], "%d", &seed) == 0) usage("Bad seed");
129 if (w < 30 && (k+m) > (1 << w)) usage("k + m is too big");
131 matrix = cauchy_original_coding_matrix(k, m, w);
132 if (matrix == NULL) {
133 usage("couldn't make coding matrix");
136 /* Print out header information to the output file. */
138 printf("<TITLE>Jerasure Example Output: cauchy_02 %d %d %d %d</TITLE>\n", k, m, w, seed);
139 printf("<h2>Jerasure Example Output: cauchy_02 %d %d %d %d</h3>\n", k, m, w, seed);
142 printf("Parameters:\n");
143 printf("<UL><LI> Number of data disks <i>(k)</i>: %d\n", k);
144 printf("<LI> Number of coding disks <i>(m)</i>: %d\n", m);
145 printf("<LI> Word size of the Galois Field: <i>(w)</i>: %d\n", w);
146 printf("<LI> Seed for the random number generator: %d\n", seed);
147 printf("<LI> Number of bytes stored per disk: %ld\n", sizeof(long)*w);
148 printf("<LI> Number of packets stored per disk: %d\n", w);
149 printf("<LI> Number of bytes per packet: %ld\n", sizeof(long));
152 /* Print out the matrix and the bitmatrix */
154 printf("Here is the matrix, which was created with <b>cauchy_original_coding_matrix()</b>.\n");
155 printf("This is not the best matrix to use, but we include it to show an example\n");
156 printf("of <b>cauchy_original_coding_matrix()</b>. For the best matrix and encoding/decoding\n");
157 printf("methodology, see <b>cauchy_04.</b><p><pre>\n");
159 jerasure_print_matrix(matrix, m, k, w);
162 bitmatrix = jerasure_matrix_to_bitmatrix(k, m, w, matrix);
165 for (i = 0; i < k*m; i++) {
166 no += cauchy_n_ones(matrix[i], w);
169 printf("The bitmatrix, which has %d one%s:<p><pre>\n", no, (no == 1) ? "" : "s");
170 jerasure_print_bitmatrix(bitmatrix, m*w, k*w, w);
175 data = talloc(char *, k);
176 dcopy = talloc(char *, k);
177 for (i = 0; i < k; i++) {
178 data[i] = talloc(char, sizeof(long)*w);
179 dcopy[i] = talloc(char, sizeof(long)*w);
180 MOA_Fill_Random_Region(data[i], sizeof(long)*w);
181 memcpy(dcopy[i], data[i], sizeof(long)*w);
184 printf("Here are the packets on the data disks:<p>\n");
185 print_array(data, k, sizeof(long)*w, sizeof(long), "D");
187 coding = talloc(char *, m);
188 ccopy = talloc(char *, m);
189 for (i = 0; i < m; i++) {
190 coding[i] = talloc(char, sizeof(long)*w);
191 ccopy[i] = talloc(char, sizeof(long)*w);
194 jerasure_bitmatrix_encode(k, m, w, bitmatrix, data, coding, w*sizeof(long), sizeof(long));
195 jerasure_get_stats(mstats);
197 schedule = jerasure_smart_bitmatrix_to_schedule(k, m, w, bitmatrix);
198 jerasure_schedule_encode(k, m, w, schedule, data, ccopy, w*sizeof(long), sizeof(long));
199 jerasure_get_stats(sstats);
201 printf("<p>Encoding with jerasure_bitmatrix_encode() - Bytes XOR'd: %.0lf.<br>\n", mstats[0]);
202 printf("Encoding with jerasure_schedule_encode() - Bytes XOR'd: %.0lf.<br>\n", sstats[0]);
204 for (i = 0; i < m; i++) {
205 if (memcmp(coding[i], ccopy[i], sizeof(long)*w) != 0) {
206 printf("Problem: the two encodings don't match on disk C%x\n", i);
211 printf("Here are the packets on the coding disks.<br>\n");
212 print_array(coding, m, sizeof(long)*w, sizeof(long), "C");
215 erasures = talloc(int, (m+1));
216 erased = talloc(int, (k+m));
217 for (i = 0; i < m+k; i++) erased[i] = 0;
218 for (i = 0; i < m; ) {
219 erasures[i] = MOA_Random_W(31, 1)%(k+m);
220 if (erased[erasures[i]] == 0) {
221 erased[erasures[i]] = 1;
222 bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], sizeof(long)*w);
227 printf("Erasures on the following devices:");
228 for (i = 0; erasures[i] != -1; i++) {
229 printf(" %c%x", ((erasures[i] < k) ? 'D' : 'C'), (erasures[i] < k ? erasures[i] : erasures[i]-k));
231 printf("<br>\nHere is the state of the system:\n<p>\n");
232 print_array(data, k, sizeof(long)*w, sizeof(long), "D");
234 print_array(coding, m, sizeof(long)*w, sizeof(long), "C");
237 jerasure_bitmatrix_decode(k, m, w, bitmatrix, 0, erasures, data, coding, w*sizeof(long), sizeof(long));
238 jerasure_get_stats(mstats);
240 printf("<p>Decoded with jerasure_bitmatrix_decode - Bytes XOR'd: %.0lf.<br>\n", mstats[0]);
242 for (i = 0; i < k; i++) if (memcmp(data[i], dcopy[i], sizeof(long)*w) != 0) {
243 printf("ERROR: D%x after decoding does not match its state before decoding!<br>\n", i);
245 for (i = 0; i < m; i++) if (memcmp(coding[i], ccopy[i], sizeof(long)*w) != 0) {
246 printf("ERROR: C%x after decoding does not match its state before decoding!<br>\n", i);
249 for (i = 0; erasures[i] != -1; i++) {
250 bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], sizeof(long)*w);
253 jerasure_schedule_decode_lazy(k, m, w, bitmatrix, erasures, data, coding, w*sizeof(long), sizeof(long), 1);
254 jerasure_get_stats(sstats);
256 printf("jerasure_schedule_decode_lazy - Bytes XOR'd: %.0lf.<br>\n", sstats[0]);
258 for (i = 0; i < k; i++) if (memcmp(data[i], dcopy[i], sizeof(long)*w) != 0) {
259 printf("ERROR: D%x after decoding does not match its state before decoding!<br>\n", i);
261 for (i = 0; i < m; i++) if (memcmp(coding[i], ccopy[i], sizeof(long)*w) != 0) {
262 printf("ERROR: C%x after decoding does not match its state before decoding!<br>\n", i);
265 printf("Here is the state of the system:\n<p>\n");
266 print_array(data, k, sizeof(long)*w, sizeof(long), "D");
268 print_array(coding, m, sizeof(long)*w, sizeof(long), "C");