lib/ccan/tally/test/run-bucket_of.c

   1 #include <ccan/tally/tally.c>
   2 #include <ccan/tap/tap.h>
   3
   4 int main(void)
   5 {
   6         unsigned int i, max_step;
   7         ssize_t min, max;
   8
   9         max = (ssize_t)~(1ULL << (sizeof(max)*CHAR_BIT - 1));
  10         min = (ssize_t)(1ULL << (sizeof(max)*CHAR_BIT - 1));
  11         max_step = sizeof(max)*CHAR_BIT;
  12
  13         plan_tests(2 + 100 + 10 + 5
  14                    + 2 + 100 + 5 + 4
  15                    + (1 << 7) * (max_step - 7));
  16
  17         /* Single step, single bucket == easy. */
  18         ok1(bucket_of(0, 0, 0) == 0);
  19
  20         /* Double step, still in first bucket. */
  21         ok1(bucket_of(0, 1, 0) == 0);
  22
  23         /* Step 8. */
  24         for (i = 0; i < 100; i++)
  25                 ok1(bucket_of(0, 3, i) == i >> 3);
  26
  27         /* 10 values in 5 buckets, step 2. */
  28         for (i = 0; i < 10; i++)
  29                 ok1(bucket_of(0, 1, i) == i >> 1);
  30
  31         /* Extreme cases. */
  32         ok1(bucket_of(min, 0, min) == 0);
  33         ok1(bucket_of(min, max_step-1, min) == 0);
  34         ok1(bucket_of(min, max_step-1, max) == 1);
  35         ok1(bucket_of(min, max_step, min) == 0);
  36         ok1(bucket_of(min, max_step, max) == 0);
  37
  38         /* Now, bucket_min() should match: */
  39         ok1(bucket_min(0, 0, 0) == 0);
  40
  41         /* Double step, val in first bucket still 0. */
  42         ok1(bucket_min(0, 1, 0) == 0);
  43
  44         /* Step 8. */
  45         for (i = 0; i < 100; i++)
  46                 ok1(bucket_min(0, 3, i) == i << 3);
  47
  48         /* 10 values in 5 buckets, step 2. */
  49         for (i = 0; i < 5; i++)
  50                 ok1(bucket_min(0, 1, i) == i << 1);
  51
  52         /* Extreme cases. */
  53         ok1(bucket_min(min, 0, 0) == min);
  54         ok1(bucket_min(min, max_step-1, 0) == min);
  55         ok1(bucket_min(min, max_step-1, 1) == 0);
  56         ok1(bucket_min(min, max_step, 0) == min);
  57
  58         /* Now, vary step and number of buckets, but bucket_min and bucket_of
  59          * must agree. */
  60         for (i = 0; i < (1 << 7); i++) {
  61                 unsigned int j;
  62                 for (j = 0; j < max_step - 7; j++) {
  63                         ssize_t val;
  64
  65                         val = bucket_min(-(ssize_t)i, j, i);
  66                         ok1(bucket_of(-(ssize_t)i, j, val) == i);
  67                 }
  68         }
  69
  70         return exit_status();
  71 }