bench: report stats in benchmark/net-pipe

benchmark/net-pipe.js

@@ -1,6 +1,7 @@
 // test the speed of .pipe() with sockets
 
 var net = require('net');
+var N = parseInt(process.argv[2]) || 100;
 var start;
 
 function Writer() {
@@ -30,6 +31,7 @@ Writer.prototype.on = function() {};
 Writer.prototype.once = function() {};
 Writer.prototype.emit = function() {};
 
+var rates = [];
 var statCounter = 0;
 Writer.prototype.printStats = function() {
   if (!this.start || !this.received)
@@ -38,18 +40,35 @@ Writer.prototype.printStats = function() {
   elapsed = elapsed[0] * 1E9 + elapsed[1];
   var bits = this.received * 8;
   var gbits = bits / (1024 * 1024 * 1024);
-  var rate = (gbits / elapsed * 1E9).toFixed(4);
-  console.log('%s Gbits/sec (%d bits / %d ns)', rate, bits, elapsed);
+  var rate = gbits / elapsed * 1E9;
+  rates.push(rate);
+  console.log('%s Gbits/sec (%d bits / %d ns)', rate.toFixed(4), bits, elapsed);
 
   // reset to keep getting instant time.
   this.start = process.hrtime();
   this.received = 0;
 
-  // 100 seconds is enough time to get a few GC runs and stabilize.
-  if (statCounter++ === 100)
+  if (++statCounter === N) {
+    report();
     process.exit(0);
+  }
 };
 
+function report() {
+  rates.sort();
+  var min = rates[0];
+  var max = rates[rates.length - 1];
+  var median = rates[rates.length >> 1];
+  var avg = 0;
+  rates.forEach(function(rate) { avg += rate });
+  avg /= rates.length;
+  console.error('min:%s avg:%s max:%s median:%s',
+                min.toFixed(2),
+                avg.toFixed(2),
+                max.toFixed(2),
+                median.toFixed(2));
+}
+
 var len = process.env.LENGTH || 16 * 1024 * 1024;
 var chunk = new Buffer(len);
 for (var i = 0; i < len; i++) {