time-to-botec

Benchmark sampling in different programming languages
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_shortOut.js (941B)

      1 /** Used to detect hot functions by number of calls within a span of milliseconds. */
      2 var HOT_COUNT = 800,
      3     HOT_SPAN = 16;
      4 
      5 /* Built-in method references for those with the same name as other `lodash` methods. */
      6 var nativeNow = Date.now;
      7 
      8 /**
      9  * Creates a function that'll short out and invoke `identity` instead
     10  * of `func` when it's called `HOT_COUNT` or more times in `HOT_SPAN`
     11  * milliseconds.
     12  *
     13  * @private
     14  * @param {Function} func The function to restrict.
     15  * @returns {Function} Returns the new shortable function.
     16  */
     17 function shortOut(func) {
     18   var count = 0,
     19       lastCalled = 0;
     20 
     21   return function() {
     22     var stamp = nativeNow(),
     23         remaining = HOT_SPAN - (stamp - lastCalled);
     24 
     25     lastCalled = stamp;
     26     if (remaining > 0) {
     27       if (++count >= HOT_COUNT) {
     28         return arguments[0];
     29       }
     30     } else {
     31       count = 0;
     32     }
     33     return func.apply(undefined, arguments);
     34   };
     35 }
     36 
     37 module.exports = shortOut;