tally: implement tally_total()

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

diff --git a/ccan/tally/test/run-total.c b/ccan/tally/test/run-total.c
new file mode 100644 (file)
index 0000000..1114a6e
--- /dev/null
+++ b/ccan/tally/test/run-total.c
@@ -0,0 +1,53 @@
+#include <ccan/tally/tally.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+       struct tally *tally;
+       ssize_t total, overflow;
+       ssize_t min, max;
+
+       max = (ssize_t)~(1ULL << (sizeof(max)*CHAR_BIT - 1));
+       min = (ssize_t)(1ULL << (sizeof(max)*CHAR_BIT - 1));
+
+       plan_tests(15);
+
+       /* Simple case. */
+       tally = tally_new(0);
+       tally_add(tally, min);
+       ok1(tally_total(tally, NULL) == min);
+       ok1(tally_total(tally, &overflow) == min);
+       ok1(overflow == -1);
+
+       /* Underflow. */
+       tally_add(tally, min);
+       total = tally_total(tally, &overflow);
+       ok1(overflow == -1);
+       ok1((size_t)total == 0);
+       ok1(tally_total(tally, NULL) == min);
+       free(tally);
+
+       /* Simple case. */
+       tally = tally_new(0);
+       tally_add(tally, max);
+       ok1(tally_total(tally, NULL) == max);
+       ok1(tally_total(tally, &overflow) == max);
+       ok1(overflow == 0);
+
+       /* Overflow into sign bit... */
+       tally_add(tally, max);
+       total = tally_total(tally, &overflow);
+       ok1(overflow == 0);
+       ok1((size_t)total == 0xFFFFFFFE);
+       ok1(tally_total(tally, NULL) == max);
+
+       /* Overflow into upper size_t. */
+       tally_add(tally, max);
+       total = tally_total(tally, &overflow);
+       ok1(overflow == 1);
+       ok1((size_t)total == 0x7FFFFFFD);
+       ok1(tally_total(tally, NULL) == max);
+       free(tally);
+
+       return exit_status();
+}