latester/histogram.h

   1 #ifndef HISTOGRAM_H
   2 #define HISTOGRAM_H
   3
   4 struct histogram {
   5         unsigned *data;
   6         unsigned out_below, out_above;
   7         unsigned allocated;
   8         unsigned resolution;
   9 };
  10
  11 int histogram_init(struct histogram *h,
  12                    unsigned max_value,
  13                    unsigned resolution)
  14 {
  15         size_t mem;
  16         h->allocated = max_value/resolution + 1;
  17         h->resolution = resolution;
  18         h->out_below = h->out_above = 0;
  19         mem = h->allocated*sizeof(*h->data);
  20         h->data = malloc(mem);
  21         if (h->data) {
  22                 memset(h->data, 0, mem);
  23                 return 0;
  24         } else
  25                 return -1;
  26 }
  27
  28 void histogram_add(struct histogram *h, int value)
  29 {
  30         if (value < 0) {
  31                 h->out_below++;
  32                 return;
  33         }
  34         unsigned index = value / h->resolution;
  35         if (index >= h->allocated) {
  36                 h->out_above++;
  37                 index = h->allocated - 1;
  38         }
  39         h->data[index]++;
  40 }
  41
  42 void histogram_fprint(struct histogram *h, FILE *f)
  43 {
  44         unsigned long long sum = 0, cum;
  45         unsigned i;
  46
  47         if (!f)
  48                 return;
  49
  50         for (i = 0; i < h->allocated; i++)
  51                 sum += h->data[i];
  52         cum = sum;
  53         for (i = 0; i < h->allocated; i++) {
  54                 if (h->data[i] != 0) {
  55                         fprintf(f, "%g %lld\n", 1e-3*(i*h->resolution), cum);
  56                 }
  57                 cum -= h->data[i];
  58         }
  59 }
  60
  61
  62 struct histogram_stats {
  63         unsigned count;
  64         unsigned long long sum;
  65         unsigned avg;
  66         unsigned below, above;  /* Count of data out of histogram range */
  67         unsigned percentile[101];
  68 };
  69
  70 void histogram_stats(struct histogram *h, struct histogram_stats *s)
  71 {
  72         unsigned long long sum;
  73         unsigned i, j;
  74
  75         if (!s)
  76                 return;
  77
  78         memset(s, 0, sizeof(*s));
  79
  80         for (i = 0; i < h->allocated; i++) {
  81                 s->count += h->data[i];
  82                 s->sum += h->data[i] * i * h->resolution;
  83         }
  84         if (s->count == 0)
  85                 return;
  86
  87         s->avg = s->sum / s->count;
  88
  89         for (i = 0, j = 0, sum = 0; i < 100; i++) {
  90                 while (sum <= i * s->count / 100)
  91                         sum += h->data[j++];
  92
  93                 s->percentile[i] = (j-1) * h->resolution;
  94         }
  95         while (sum < i * s->count / 100)
  96                 sum += h->data[j++];
  97         s->percentile[100] = (j-1) * h->resolution;
  98
  99         s->below = h->out_below;
 100         s->above = h->out_above;
 101 }
 102
 103 #endif