node/lib/internal/freelist.js

'use strict';

// This is a free list to avoid creating so many of the same object.
exports.FreeList = function(name, max, constructor) {
  this.name = name;
  this.constructor = constructor;
  this.max = max;
  this.list = [];
};

exports.FreeList.prototype.alloc = function() {
  return this.list.length ? this.list.pop() :
    this.constructor.apply(this, arguments);
};


exports.FreeList.prototype.free = function(obj) {
  if (this.list.length < this.max) {
    this.list.push(obj);
    return true;
  }
  return false;
};