/* Examples/cauchy_02.c
Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure Coding Techniques

Revision 1.2A
May 24, 2011

James S. Plank
Department of Electrical Engineering and Computer Science
University of Tennessee
Knoxville, TN 37996
plank@cs.utk.edu

Copyright (c) 2011, James S. Plank
All rights reserved.

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modification, are permitted provided that the following conditions
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 - 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.

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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
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 */


/*
	revised by S. Simmerman
	2/25/08  
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "jerasure.h"
#include "cauchy.h"

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

usage(char *s)
{
  fprintf(stderr, "usage: cauchy_02 k m w - Scheduled CRS coding example with the original matrix in  GF(2^w).\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "       k+m must be <= 2^w.  It sets up a Cauchy distribution matrix using the original\n");
  fprintf(stderr, "       Cauchy Distribution matrix construction algorithm, then it encodes\n");
  fprintf(stderr, "       k devices of w*%d bytes using smart bit-matrix scheduling.\n", sizeof(long));
  fprintf(stderr, "       It decodes using bit-matrix scheduling as well.\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "This demonstrates: cauchy_original_coding_matrix()\n");
  fprintf(stderr, "                   cauchy_xy_coding_matrix()\n");
  fprintf(stderr, "                   cauchy_n_ones()\n");
  fprintf(stderr, "                   jerasure_smart_bitmatrix_to_schedule()\n");
  fprintf(stderr, "                   jerasure_schedule_encode()\n");
  fprintf(stderr, "                   jerasure_schedule_decode_lazy()\n");
  fprintf(stderr, "                   jerasure_print_matrix()\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 *matrix, *bitmatrix, *m2, *x, *y;
  char **data, **coding, **ptrs;
  int **smart;
  int no;
  int *erasures, *erased;
  double stats[3];
  
  if (argc != 4) 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");

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

  no = 0;
  for (i = 0; i < k*m; i++) {
    no += cauchy_n_ones(matrix[i], w);
  }
  printf("Matrix has %d ones\n\n", no);
  jerasure_print_matrix(matrix, m, k, w);
  printf("\n", no);
  bitmatrix = jerasure_matrix_to_bitmatrix(k, m, w, matrix);

  smart = jerasure_smart_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, smart, 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);
  
  x = talloc(int, m);
  y = talloc(int, k);
  if (x == NULL || y == NULL) { perror("malloc"); exit(1); }
  for (i = 0; i < m; i++) x[i] = i;
  for (i = 0; i < k; i++) y[i] = m+i;
  m2 = cauchy_xy_coding_matrix(k, m, w, x, y);
  if (memcmp(matrix, m2, sizeof(int)*k*m) != 0) {
    printf("Error -- the matrices made by original and xy don't match\n");
    exit(1);
  } else {
    printf("Generated the identical matrix using cauchy_xy_coding_matrix()\n");
  }


  return 0;
}