benchmark: add util.format benchmark

PR-URL: #5360 Reviewed-By: James M Snell <[email protected]>

Author: evanlucas

benchmark/util/format.js

@@ -0,0 +1,40 @@
+'use strict';
+
+constutil=require('util');
+constcommon=require('../common');
+constv8=require('v8');
+constbench=common.createBenchmark(main,{
+n: [1e6]
+,type: ['string',
+'number',
+'object',
+'unknown',
+'no-replace']
+});
+
+constinputs={
+'string': ['Hello, my name is %s','fred'],
+'number': ['Hi, I was born in %d',1942],
+'object': ['An error occurred %j',{msg: 'This is an error',code: 'ERR'}],
+'unknown': ['hello %a','test'],
+'no-replace': [1,2]
+};
+
+functionmain(conf){
+constn=conf.n|0;
+consttype=conf.type;
+
+constinput=inputs[type];
+
+v8.setFlagsFromString('--allow_natives_syntax');
+
+util.format(input[0],input[1]);
+eval('%OptimizeFunctionOnNextCall(util.format)');
+util.format(input[0],input[1]);
+
+bench.start();
+for(vari=0;i<n;i++){
+util.format(input[0],input[1]);
+}
+bench.end(n);
+}