Merge branch 'master' of git@github.com:steveyen/moxi

agent_ping.c

@@ -322,6 +322,9 @@ void ping_server(char *server_name,
                                 "max", recipe_stats.max);
                     stat_report(val_name, vlen, recipes[j].name,
                                 "stddev", recipe_stats.stddev);
+                    stat_report(val_name, vlen, recipes[j].name,
+                                "95th", recipe_stats.ninetyfifth);
+
 
                     snprintf(val_name, vlen, "%s_fail", recipes[j].name);
                     int_report(val_name, failures);

check_util.c

@@ -189,6 +189,8 @@ START_TEST (test_compute_stats)
     fail_unless(almost_equal(stats.avg, 5.0), "Avg should be 5");
     fail_unless(almost_equal(stats.stddev, 2.0),
                 "Standard devition should be 2.");
+    fail_unless(almost_equal(stats.ninetyfifth, 9.0),
+                "95th %%ile should be 9.");
 }
 END_TEST
 

util.c

@@ -119,7 +119,14 @@ double timeval_to_double(struct timeval tv)
     return (double)tv.tv_sec + ((double)tv.tv_usec / 1000000);
 }
 
-void compute_stats(struct moxi_stats *out, const double *vals, int num_vals)
+static int cmp_doubles(const void *pa, const void *pb)
+{
+    double a = *(double*)pa;
+    double b = *(double*)pb;
+    return a == b ? 0 : (a < b ? -1 : 1);
+}
+
+void compute_stats(struct moxi_stats *out, double *vals, int num_vals)
 {
     assert(out);
     assert(vals);
@@ -147,4 +154,8 @@ void compute_stats(struct moxi_stats *out, const double *vals, int num_vals)
     }
 
     out->stddev = sqrt(sum / num_vals);
+
+    // 95th %ile
+    qsort(vals, num_vals, sizeof(double), cmp_doubles);
+    out->ninetyfifth = vals[(int)((float)num_vals * 0.95)];
 }

util.h

@@ -32,9 +32,14 @@ struct moxi_stats {
     double max;
     double avg;
     double stddev;
+    double ninetyfifth;
 };
 
 /**
  * Compute some statistics over a sequence.
+ *
+ * @param out accumulated stats for input values
+ * @param vals input values (note: these will be reordered)
+ * @param num_values the number of values to be processed
  */
-void compute_stats(struct moxi_stats *out, const double *vals, int num_vals);
+void compute_stats(struct moxi_stats *out, double *vals, int num_vals);