jerasure/Examples/liberation_01.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"
#include "liberation.h"

#define talloc(type, num) (type *) malloc(sizeof(type)*(num))

usage(char *s)
{
  fprintf(stderr, "usage: liberation_01 k w - Liberation RAID-6 coding/decoding example in GF(2^w).\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "       w must be prime and k <= w.  It sets up a Liberation bit-matrix\n");
  fprintf(stderr, "       then it encodes k devices of w*%d bytes using dumb bit-matrix scheduling.\n", sizeof(long));
  fprintf(stderr, "       It decodes using smart bit-matrix scheduling.\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "This demonstrates: liberation_coding_bitmatrix()\n");
  fprintf(stderr, "                   jerasure_smart_bitmatrix_to_schedule()\n");
  fprintf(stderr, "                   jerasure_dumb_bitmatrix_to_schedule()\n");
  fprintf(stderr, "                   jerasure_schedule_encode()\n");
  fprintf(stderr, "                   jerasure_schedule_decode_lazy()\n");
  fprintf(stderr, "                   jerasure_print_bitmatrix()\n");
  fprintf(stderr, "                   jerasure_get_stats()\n");
  if (s != NULL) fprintf(stderr, "%s\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;
  int *bitmatrix;
  char **data, **coding, **ptrs;
  int **dumb;
  int *erasures, *erased;
  double stats[3];
  
  if (argc != 3) usage(NULL);
  if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k");
  if (sscanf(argv[2], "%d", &w) == 0 || w <= 0 || w > 32) usage("Bad w");
  m = 2;
  if (w < k) usage("k is too big");

  bitmatrix = liberation_coding_bitmatrix(k, w);
  if (bitmatrix == NULL) {
    usage("couldn't make coding matrix");
  }

  printf("Coding Bit-Matrix:\n\n");
  jerasure_print_bitmatrix(bitmatrix, w*m, w*k, w);
  printf("\n");

  dumb = jerasure_dumb_bitmatrix_to_schedule(k, m, w, bitmatrix);

  srand48(0);
  data = talloc(char *, k);
  for (i = 0; i < k; i++) {
    data[i] = talloc(char, sizeof(long)*w);
    for (j = 0; j < w; j++) {
      l = lrand48();
      memcpy(data[i]+j*sizeof(long), &l, sizeof(long));
    }
  }

  coding = talloc(char *, m);
  for (i = 0; i < m; i++) {
    coding[i] = talloc(char, sizeof(long)*w);
  }

  jerasure_schedule_encode(k, m, w, dumb, data, coding, w*sizeof(long), sizeof(long));
  jerasure_get_stats(stats);
  printf("Smart Encoding Complete: - %.0lf XOR'd bytes\n\n", stats[0]);
  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;
  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], sizeof(long)*w);
      i++;
    }
  }
  erasures[i] = -1;

  printf("Erased %d random devices:\n\n", m);
  print_data_and_coding(k, m, w, sizeof(long), data, coding);
  
  jerasure_schedule_decode_lazy(k, m, w, bitmatrix, erasures, data, coding, w*sizeof(long), sizeof(long), 1);
  jerasure_get_stats(stats);

  printf("State of the system after decoding: %.0lf XOR'd bytes\n\n", stats[0]);
  print_data_and_coding(k, m, w, sizeof(long), data, coding);
  
  return 0;
}