"use strict";function _classCallCheck(t,e){if(!(t instanceof e))throw new TypeError("Cannot call a class as a function")}var Buffer=require("safe-buffer").Buffer,util=require("util");function copyBuffer(t,e,i){t.copy(e,i)}module.exports=function(){function t(){_classCallCheck(this,t),this.head=null,this.tail=null,this.length=0}return t.prototype.push=function(t){var e={data:t,next:null};this.length>0?this.tail.next=e:this.head=e,this.tail=e,++this.length},t.prototype.unshift=function(t){var e={data:t,next:this.head};0===this.length&&(this.tail=e),this.head=e,++this.length},t.prototype.shift=function(){if(0!==this.length){var t=this.head.data;return 1===this.length?this.head=this.tail=null:this.head=this.head.next,--this.length,t}},t.prototype.clear=function(){this.head=this.tail=null,this.length=0},t.prototype.join=function(t){if(0===this.length)return"";for(var e=this.head,i=""+e.data;e=e.next;)i+=t+e.data;return i},t.prototype.concat=function(t){if(0===this.length)return Buffer.alloc(0);if(1===this.length)return this.head.data;for(var e=Buffer.allocUnsafe(t>>>0),i=this.head,n=0;i;)copyBuffer(i.data,e,n),n+=i.data.length,i=i.next;return e},t}(),util&&util.inspect&&util.inspect.custom&&(module.exports.prototype[util.inspect.custom]=function(){var t=util.inspect({length:this.length});return this.constructor.name+" "+t});