gistfile1.js

var fastQueue = module.exports = function fastQueue(){
  this.tail = [];
  this.head = Array.prototype.slice.call(arguments);
  this.offset = 0;
};


fastQueue.prototype.shift = function shift() {
  if (this.offset === this.head.length) {
    var tmp = this.head;
    tmp.length = 0;
    this.head = this.tail;
    this.tail = tmp;
    this.offset = 0;
    if (this.head.length === 0) return;
  }
  return this.head[this.offset++];
};

fastQueue.prototype.push = function push(item) {
  return this.tail.push(item);
};

Object.defineProperty(fastQueue, "length", {
  get: function() {
    return this.head.length - this.offset + this.tail.length;
  }
});