Jens Axboe | 6ff3885 | 2012-11-06 16:09:14 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Generate/analyze pareto/zipf distributions to better understand |
| 3 | * what an access pattern would look like. |
| 4 | * |
| 5 | * For instance, the following would generate a zipf distribution |
| 6 | * with theta 1.2, using 100,000 values and split the reporting into |
| 7 | * 20 buckets: |
| 8 | * |
| 9 | * t/genzipf zipf 1.2 100000 20 |
| 10 | * |
| 11 | */ |
| 12 | #include <stdio.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <fcntl.h> |
| 15 | #include <string.h> |
| 16 | |
| 17 | #include "../lib/zipf.h" |
| 18 | |
| 19 | static int val_cmp(const void *p1, const void *p2) |
| 20 | { |
| 21 | const unsigned long *v1 = p1; |
| 22 | const unsigned long *v2 = p2; |
| 23 | |
| 24 | return *v1 - *v2; |
| 25 | } |
| 26 | |
| 27 | int main(int argc, char *argv[]) |
| 28 | { |
| 29 | unsigned long nranges, output_nranges; |
| 30 | unsigned long *vals; |
| 31 | unsigned long i, j, nr_vals, cur_vals, max_val, interval, total; |
| 32 | double *output; |
| 33 | struct zipf_state zs; |
| 34 | int use_zipf; |
| 35 | double val; |
| 36 | |
| 37 | if (argc < 4) { |
| 38 | printf("%s: {zipf,pareto} val values [output ranges]\n", argv[0]); |
| 39 | return 1; |
| 40 | } |
| 41 | |
| 42 | if (!strcmp(argv[1], "zipf")) |
| 43 | use_zipf = 1; |
| 44 | else if (!strcmp(argv[1], "pareto")) |
| 45 | use_zipf = 0; |
| 46 | else { |
| 47 | printf("Bad distribution type <%s>\n", argv[1]); |
| 48 | return 1; |
| 49 | } |
| 50 | |
| 51 | val = atof(argv[2]); |
| 52 | nranges = strtoul(argv[3], NULL, 10); |
| 53 | if (argc == 5) |
| 54 | output_nranges = strtoul(argv[4], NULL, 10); |
| 55 | else |
| 56 | output_nranges = nranges; |
| 57 | |
| 58 | printf("Generating %s distribution with %f input and %lu ranges\n", use_zipf ? "zipf" : "pareto", val, nranges); |
| 59 | getchar(); |
| 60 | |
| 61 | if (use_zipf) |
| 62 | zipf_init(&zs, nranges, val); |
| 63 | else |
| 64 | pareto_init(&zs, nranges, val); |
| 65 | |
| 66 | vals = malloc(nranges * sizeof(unsigned long)); |
| 67 | |
| 68 | total = max_val = nr_vals = 0; |
| 69 | for (i = 0; i < nranges; i++) { |
| 70 | if (use_zipf) |
| 71 | vals[nr_vals] = zipf_next(&zs); |
| 72 | else |
| 73 | vals[nr_vals] = pareto_next(&zs); |
| 74 | |
| 75 | if (vals[nr_vals] > max_val) |
| 76 | max_val = vals[nr_vals]; |
| 77 | nr_vals++; |
| 78 | } |
| 79 | |
| 80 | qsort(vals, nr_vals, sizeof(unsigned long), val_cmp); |
| 81 | |
| 82 | interval = (max_val + output_nranges - 1) / output_nranges; |
| 83 | |
| 84 | output = malloc(output_nranges * sizeof(double)); |
| 85 | |
| 86 | for (i = j = 0, cur_vals = 1; i < nr_vals; i++) { |
| 87 | if (vals[i] > interval) { |
| 88 | output[j] = (double) cur_vals / (double) nr_vals; |
| 89 | output[j] *= 100.0; |
| 90 | j++; |
| 91 | total += cur_vals; |
| 92 | cur_vals = 1; |
| 93 | interval += (max_val + output_nranges - 1) / output_nranges; |
| 94 | continue; |
| 95 | } |
| 96 | cur_vals++; |
| 97 | } |
| 98 | |
| 99 | output[j] = (double) cur_vals / (double) nr_vals; |
| 100 | output[j] *= 100.0; |
| 101 | j++; |
| 102 | total += cur_vals; |
| 103 | |
| 104 | for (i = 0; i < j; i++) |
| 105 | printf("%.2f%%\n", output[i]); |
| 106 | |
| 107 | free(output); |
| 108 | free(vals); |
| 109 | return 0; |
| 110 | } |