Fixing quantile again, check min_rank

statsite · Feb 28, 2016 · ea58c73 · ea58c73
1 parent 8c43e88
commit ea58c73
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 3 deletions.
diff --git a/src/cm_quantile.c b/src/cm_quantile.c
@@ -163,16 +163,16 @@ int cm_flush(cm_quantile *cm) {
  * @return The value on success or 0.
  */
 double cm_query(cm_quantile *cm, double quantile) {
-    uint64_t rank = floor(quantile * cm->num_values);
+    uint64_t rank = ceil(quantile * cm->num_values);
 	uint64_t min_rank=0;
     uint64_t max_rank;
-	uint64_t threshold = floor(cm_threshold(cm, rank) / 2.);
+	uint64_t threshold = ceil(cm_threshold(cm, rank) / 2.);
 
     cm_sample *prev = cm->samples;
     cm_sample *current = cm->samples;
     while (current) {
         max_rank = min_rank + current->width + current->delta;
-        if (max_rank > rank + threshold) {
+        if (max_rank > rank + threshold || min_rank > rank) {
             break;
         }
         min_rank += current->width;

diff --git a/tests/runner.c b/tests/runner.c
@@ -57,6 +57,7 @@ int main(void)
     tcase_add_test(tc2, test_cm_init_add_loop_destroy);
     tcase_add_test(tc2, test_cm_init_query_destroy);
     tcase_add_test(tc2, test_cm_init_add_query_destroy);
+    tcase_add_test(tc2, test_cm_init_add3_query_destroy);
     tcase_add_test(tc2, test_cm_init_add_negative_query_destroy);
     tcase_add_test(tc2, test_cm_init_add_loop_query_destroy);
     tcase_add_test(tc2, test_cm_init_add_loop_tail_query_destroy);

diff --git a/tests/test_cm_quantile.c b/tests/test_cm_quantile.c
@@ -110,6 +110,33 @@ START_TEST(test_cm_init_add_query_destroy)
 }
 END_TEST
 
+START_TEST(test_cm_init_add3_query_destroy)
+{
+    cm_quantile cm;
+    double quants[] = {0.5, 0.90, 0.99};
+    int res = init_cm_quantile(0.01, (double*)&quants, 3, &cm);
+    fail_unless(res == 0);
+
+    res = cm_add_sample(&cm, 100.0);
+    fail_unless(res == 0);
+
+    res = cm_add_sample(&cm, 200.0);
+    fail_unless(res == 0);
+
+    res = cm_add_sample(&cm, 300.0);
+    fail_unless(res == 0);
+
+    res = cm_flush(&cm);
+    fail_unless(res == 0);
+
+    double val = cm_query(&cm, 0.5);
+    fail_unless(val == 200.0);
+
+    res = destroy_cm_quantile(&cm);
+    fail_unless(res == 0);
+}
+END_TEST
+
 START_TEST(test_cm_init_add_negative_query_destroy)
 {
     cm_quantile cm;