new Function cache.js

/*
  This test detects if engine cache bytecode or not.
*/

var _main = function()
{
  var bigCode = String(_main);

  bigCode = bigCode.slice(bigCode.indexOf('{') + 1, bigCode.lastIndexOf('}')); 
  bigCode = new Array(11).join(bigCode); // *= 10 to make really big code 

  bigCode += 'return ';

  _speedTest(
    [
      function(n)
      {
        var bigCodeC = bigCode;
        var _random = Math.random;
        var i = n; while(i--)
        {
          new Function(bigCodeC + _random());
        }    
      },
      function(n)
      {
        var bigCodeC = bigCode;
        var _random = Math.random;
        var i = n; while(i--)
        {
          new Function(bigCodeC + '0.10101010');
          '' + _random();
        }    
      },
      (function()
      {
        var fnCache = {};

        return function(n)
        {
          var bigCodeC = bigCode;
          var _random = Math.random;
          var i = n; while(i--)
          {
            var code = bigCodeC + '0.10101010';
            
            fnCache[code] || (fnCache[code] = new Function(code));
            '' + _random();
          }    
        }
      })();  
    ],
    1000
  );
}; // _main  

/*
  chrome8
    0: 2648 ms
    1: 376 ms
    2: 385 ms

  opera10.62
    0: 3372 ms
    1: 3304 ms
    2: 12 ms
    
  ff3.6
    0: 2892 ms
    1: 3028 ms
    2: 117 ms

  ff4
    0: 3322 ms
    1: 3490 ms
    2: 118 ms  
  
  ie8
    0: 1221 ms
    1: 1252 ms
    2: 150 ms  
  
  safari5.0.2
    0: 1880 ms
    1: 1896 ms
    2: 146 ms  
*/

/*
  As you see all engines hasnt bytecode cache except V8, but V8 internal bytecode cache speed similar artificial.
  But do we need bytecode cache? I guess - no. 
  Because <new Function> is used very rarely and same code may be is passed in 0.1% cases.
  Also bytecode cache requires smart garbage collection mechanism to prevent unefficient memory usage.
*/