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authorFlorian Dold <florian.dold@gmail.com>2020-01-15 15:17:02 +0100
committerFlorian Dold <florian.dold@gmail.com>2020-01-15 15:17:25 +0100
commitda5b3ba8aeb9d47e4f99cd22847c9b539ff8ee2b (patch)
tree6e67e1d08fd941144f464dfe55b8835db65687e6 /src/util
parentb37fff0d5b08926169633ce8822de7ac616ae169 (diff)
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round amounts based on config, do unit test for rounding
Diffstat (limited to 'src/util')
-rw-r--r--src/util/amount.c13
-rw-r--r--src/util/test_amount.c23
2 files changed, 32 insertions, 4 deletions
diff --git a/src/util/amount.c b/src/util/amount.c
index edb9dc06..48f5d989 100644
--- a/src/util/amount.c
+++ b/src/util/amount.c
@@ -673,19 +673,24 @@ TALER_amount_divide (struct TALER_Amount *result,
/**
- * Round the amount to something that can be
- * transferred on the wire.
+ * Round the amount to something that can be transferred on the wire.
*
* @param[in,out] amount amount to round down
+ * @param max_fractional_digits number of fractional digits to round down to
* @return #GNUNET_OK on success, #GNUNET_NO if rounding was unnecessary,
* #GNUNET_SYSERR if the amount or currency was invalid
*/
int
-TALER_amount_round (struct TALER_Amount *amount)
+TALER_amount_round_down (struct TALER_Amount *amount,
+ uint8_t max_fractional_digits)
{
uint32_t delta;
+ uint32_t divisor = 1;
- delta = amount->fraction % (TALER_AMOUNT_FRAC_BASE / 100);
+ for (unsigned int i = 0; i < max_fractional_digits; i++)
+ divisor *= 10;
+
+ delta = amount->fraction % (TALER_AMOUNT_FRAC_BASE / divisor);
if (0 == delta)
return GNUNET_NO;
amount->fraction -= delta;
diff --git a/src/util/test_amount.c b/src/util/test_amount.c
index d9110eaf..4eeccd7e 100644
--- a/src/util/test_amount.c
+++ b/src/util/test_amount.c
@@ -234,6 +234,29 @@ main (int argc,
GNUNET_assert (0 == a2.value);
GNUNET_assert (1 == a2.fraction);
+ /* test rounding #1 */
+
+ GNUNET_assert (GNUNET_OK ==
+ TALER_string_to_amount ("EUR:4.001",
+ &a1));
+ GNUNET_assert (GNUNET_OK ==
+ TALER_string_to_amount ("EUR:4",
+ &a2));
+
+ GNUNET_assert (GNUNET_OK == TALER_amount_round_down (&a1, 2));
+ GNUNET_assert (GNUNET_NO == TALER_amount_round_down (&a1, 2));
+ GNUNET_assert (0 == TALER_amount_cmp (&a1, &a2));
+
+ /* test rounding #2 */
+
+ GNUNET_assert (GNUNET_OK ==
+ TALER_string_to_amount ("EUR:4.001",
+ &a1));
+ GNUNET_assert (GNUNET_OK ==
+ TALER_string_to_amount ("EUR:4.001",
+ &a2));
+ GNUNET_assert (GNUNET_NO == TALER_amount_round_down (&a1, 3));
+ GNUNET_assert (0 == TALER_amount_cmp (&a1, &a2));
return 0;
}