'use strict';

var Buffer = require('buffer').Buffer; /*<replacement>*/ var bufferShim = require('buffer-shims'); /*</replacement>*/

module.exports = BufferList;

function BufferList() {

this.head = null;
this.tail = null;
this.length = 0;

}

BufferList.prototype.push = function (v) {

var entry = { data: v, next: null };
if (this.length > 0) this.tail.next = entry;else this.head = entry;
this.tail = entry;
++this.length;

};

BufferList.prototype.unshift = function (v) {

var entry = { data: v, next: this.head };
if (this.length === 0) this.tail = entry;
this.head = entry;
++this.length;

};

BufferList.prototype.shift = function () {

if (this.length === 0) return;
var ret = this.head.data;
if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
--this.length;
return ret;

};

BufferList.prototype.clear = function () {

this.head = this.tail = null;
this.length = 0;

};

BufferList.prototype.join = function (s) {

if (this.length === 0) return '';
var p = this.head;
var ret = '' + p.data;
while (p = p.next) {
  ret += s + p.data;
}return ret;

};

BufferList.prototype.concat = function (n) {

if (this.length === 0) return bufferShim.alloc(0);
if (this.length === 1) return this.head.data;
var ret = bufferShim.allocUnsafe(n >>> 0);
var p = this.head;
var i = 0;
while (p) {
  p.data.copy(ret, i);
  i += p.data.length;
  p = p.next;
}
return ret;

};