revert slice arguments to args

- revert 4ecffe8d22
- also add benchmark

benchmark/arguments-to-args.js

@@ -0,0 +1,61 @@
+var Benchmark = require('benchmark');
+var benchmarks = require('beautify-benchmark');
+
+var suite = new Benchmark.Suite();
+
+function slice() {
+  return Array.prototype.slice.call(arguments);
+}
+
+function slice0() {
+  return Array.prototype.slice.call(arguments, 0);
+}
+
+function forLoop() {
+  var args = new Array(arguments.length);
+  for(var i = 0; i < args.length; i++) {
+    args[i] = arguments[i];
+  }
+  return args;
+}
+
+console.log('slice(0, 1, 2, 3, 4, 5, 6, 7): %j', slice(0, 1, 2, 3, 4, 5, 6, 7));
+console.log('slice0(0, 1, 2, 3, 4, 5, 6, 7): %j', slice0(0, 1, 2, 3, 4, 5, 6, 7));
+console.log('forLoop(0, 1, 2, 3, 4, 5, 6, 7): %j', forLoop(0, 1, 2, 3, 4, 5, 6, 7));
+
+suite
+
+.add('Array.prototype.slice.call(arguments)', function() {
+  slice(0, 1, 2, 3, 4, 5, 6, 7)
+})
+.add('Array.prototype.slice.call(arguments, 0)', function() {
+  slice0(0, 1, 2, 3, 4, 5, 6, 7)
+})
+.add('for(var i = 0; i < args.length; i++) {}', function() {
+  forLoop(0, 1, 2, 3, 4, 5, 6, 7)
+})
+
+.on('cycle', function(event) {
+  benchmarks.add(event.target);
+})
+.on('start', function(event) {
+  console.log('\n  arguments to args Benchmark\n  node version: %s, date: %s\n  Starting...',
+    process.version, Date());
+})
+.on('complete', function done() {
+  benchmarks.log();
+})
+.run({ async: false });
+
+// slice(0, 1, 2, 3, 4, 5, 6, 7): [0,1,2,3,4,5,6,7]
+// slice0(0, 1, 2, 3, 4, 5, 6, 7): [0,1,2,3,4,5,6,7]
+// forLoop(0, 1, 2, 3, 4, 5, 6, 7): [0,1,2,3,4,5,6,7]
+//
+//   arguments to args Benchmark
+//   node version: v2.4.0, date: Tue Jul 21 2015 01:39:54 GMT+0800 (CST)
+//   Starting...
+//   3 tests completed.
+//
+//   Array.prototype.slice.call(arguments)    x  4,537,649 ops/sec ±1.18% (94 runs sampled)
+//   Array.prototype.slice.call(arguments, 0) x  4,605,132 ops/sec ±0.87% (96 runs sampled)
+//   for(var i = 0; i < args.length; i++) {}  x 30,435,436 ops/sec ±0.91% (93 runs sampled)

index.js

@@ -133,8 +133,11 @@ module.exports = function (app, options) {
     }
 
     // __(key, value1, value2, value3, value4, value5, ...)
-    var args = Array.prototype.slice.call(arguments);
+    var args = new Array(arguments.length);
     args[0] = text;
+    for(var i = 1; i < args.length; i++) {
+      args[i] = arguments[i];
+    }
     return util.format.apply(util, args);
   };
 

package.json

@@ -18,14 +18,16 @@
   "dependencies": {
     "debug": "~2.2.0",
     "humanize-ms": "~1.0.1",
-    "ini": "~1.3.3"
+    "ini": "~1.3.4"
   },
   "devDependencies": {
     "autod": "*",
+    "beautify-benchmark": "~0.2.4",
+    "benchmark": "~1.0.0",
     "contributors": "*",
     "istanbul-harmony": "*",
     "jshint": "*",
-    "koa": "~0.20.0",
+    "koa": "~0.21.0",
     "mm": "~1.1.0",
     "mocha": "*",
     "pedding": "~1.0.0",