Add request processing time logging to middleware benchmark

benchmarks/middleware.js

@@ -13,7 +13,36 @@ while (n--) {
   });
 }
 
+app.use(function(req, res){var express = require('..');
+var app = express();
+
+// Number of middleware
+var n = parseInt(process.env.MW || '1', 10);
+console.log('  %s middleware', n);
+
+// Adding a middleware to log the request processing time
+app.use(function(req, res, next){
+  var start = process.hrtime();
+  res.on('finish', () => {
+    var diff = process.hrtime(start);
+    console.log(`Request processing time: ${diff[0] * 1e9 + diff[1]} nanoseconds`);
+  });
+  next();
+});
+
+// Adding user-defined middlewares
+while (n--) {
+  app.use(function(req, res, next){
+    next();
+  });
+}
+
 app.use(function(req, res){
+  res.send('Hello World');
+});
+
+app.listen(3333, () => console.log('Server running on port 3333'));
+
   res.send('Hello World')
 });