tally: new module for tallying numbers.

[ccan] / ccan / tally / test / run-bucket_of.c

diff --git a/ccan/tally/test/run-bucket_of.c b/ccan/tally/test/run-bucket_of.c
new file mode 100644 (file)
index 0000000..857f2bc
--- /dev/null
+++ b/ccan/tally/test/run-bucket_of.c
@@ -0,0 +1,71 @@
+#include <ccan/tally/tally.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+       unsigned int i, max_step;
+       ssize_t min, max;
+
+       max = (ssize_t)~(1ULL << (sizeof(max)*CHAR_BIT - 1));
+       min = (ssize_t)(1ULL << (sizeof(max)*CHAR_BIT - 1));
+       max_step = sizeof(max)*CHAR_BIT;
+
+       plan_tests(2 + 100 + 10 + 5
+                  + 2 + 100 + 5 + 4
+                  + (1 << 7) * (max_step - 7));
+
+       /* Single step, single bucket == easy. */ 
+       ok1(bucket_of(0, 0, 0) == 0);
+
+       /* Double step, still in first bucket. */
+       ok1(bucket_of(0, 1, 0) == 0);
+
+       /* Step 8. */
+       for (i = 0; i < 100; i++)
+               ok1(bucket_of(0, 3, i) == i >> 3);
+
+       /* 10 values in 5 buckets, step 2. */
+       for (i = 0; i < 10; i++)
+               ok1(bucket_of(0, 1, i) == i >> 1);
+
+       /* Extreme cases. */
+       ok1(bucket_of(min, 0, min) == 0);
+       ok1(bucket_of(min, max_step-1, min) == 0);
+       ok1(bucket_of(min, max_step-1, max) == 1);
+       ok1(bucket_of(min, max_step, min) == 0);
+       ok1(bucket_of(min, max_step, max) == 0);
+
+       /* Now, bucket_min() should match: */
+       ok1(bucket_min(0, 0, 0) == 0);
+
+       /* Double step, val in first bucket still 0. */
+       ok1(bucket_min(0, 1, 0) == 0);
+
+       /* Step 8. */
+       for (i = 0; i < 100; i++)
+               ok1(bucket_min(0, 3, i) == i << 3);
+
+       /* 10 values in 5 buckets, step 2. */
+       for (i = 0; i < 5; i++)
+               ok1(bucket_min(0, 1, i) == i << 1);
+
+       /* Extreme cases. */
+       ok1(bucket_min(min, 0, 0) == min);
+       ok1(bucket_min(min, max_step-1, 0) == min);
+       ok1(bucket_min(min, max_step-1, 1) == 0);
+       ok1(bucket_min(min, max_step, 0) == min);
+
+       /* Now, vary step and number of buckets, but bucket_min and bucket_of
+        * must agree. */
+       for (i = 0; i < (1 << 7); i++) {
+               unsigned int j;
+               for (j = 0; j < max_step - 7; j++) {
+                       ssize_t val;
+
+                       val = bucket_min(-(ssize_t)i, j, i);
+                       ok1(bucket_of(-(ssize_t)i, j, val) == i);
+               }
+       }
+
+       return exit_status();
+}