socketpeer.js

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.SocketPeer = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({"/browser":[function(require,module,exports){
/* jshint browserify: true */
/* global WebSocket */

var events = require('events');
var inherits = require('inherits');  // A tiny lib containing `util.inherits`.

var extend = require('xtend/mutable');
var SimplePeer = require('simple-peer');

var EventEmitter = events.EventEmitter;

/**
 * A WebRTC/WebSocket peer connection.
 * @param {Object} opts
 */
function SocketPeer (opts) {
  var self = this;

  if (!(self instanceof SocketPeer)) {
    return new SocketPeer(opts);
  }

  opts = opts || {};

  EventEmitter.call(self);

  self._connections = {
    socket: {success: 0, error: 0, attempt: 0},
    rtc: {success: 0, error: 0, attempt: 0}
  };
  self.peer = null;
  self.rtcConnected = false;
  self.socketConnected = false;

  extend(self, {
    pairCode: 'pairCode' in opts ? opts.pairCode : null,
    socketFallback: 'socketFallback' in opts ? opts.socketFallback : true,
    socket: 'socket' in opts ? opts.socket : null,
    stream: 'stream' in opts ? opts.stream : null,
    url: 'url' in opts ? opts.url : 'http://localhost',
    reconnect: 'reconnect' in opts ? opts.reconnect : true,
    reconnectDelay: 'reconnectDelay' in opts ? opts.reconnectDelay : 1000,
    timeout: 'timeout' in opts ? opts.timeout : 0,
    autoconnect: 'autoconnect' in opts ? opts.autoconnect : true,
    debug: 'debug' in opts ? opts.debug : false
  }, opts);

  self._debug('New peer');

  self.on('peer.found', function (data) {
    self.socketConnected = true;
    clearTimeout(self._socketConnectTimeout);
    clearTimeout(self._socketReconnectDelayTimeout);
    self._connections.socket.attempt = 0;
    self._connections.socket.success++;

    self.emit('connect');
    if (self._connections.socket.success > 0) {
      self.emit('reconnect');
    }

    self.initiator = data.initiator;

    if (data.initiator) {
      self._send('rtc.connect');
      self._rtcInit();
    }
  });
  self.on('rtc.signal', self._rtcSignal);
  self.on('rtc.connect', function () {
    self._rtcInit();
  });

  self.on('busy', function () {
    self._socketError(new Error('Pair code "' + self.pairCode + '" already in use'));
    self.socket.close();
  });

  if (self.autoconnect) {
    setTimeout(function () {
      self.connect();
    }, 0);
  }
}

inherits(SocketPeer, EventEmitter);

SocketPeer.prototype.pair = function (pairCode) {
  var self = this;

  if (typeof pairCode !== 'undefined') {
    self.pairCode = pairCode;
  }

  self._send('pair', self.pairCode);
};

SocketPeer.prototype.connect = function () {
  var self = this;

  self._connections.socket.attempt++;

  if (self.socketConnected) {
    console.warn('Socket already connected');
    return;
  }

  if (self.timeout) {
    self._socketConnectTimeout = setTimeout(function () {
      self.socket.close();
      var err = new Error('Connection timeout after ' + self.timeout + ' ms');
      self.emit('connect_timeout', err);
      self._socketError(err);
    }, self.timeout);
  }

  self.socket = new WebSocket(self.url.replace(/^http/, 'ws'));
  self.socket.onopen = function () {
    self.pair();
  };
  self.socket.onerror = function (event) {
    self._socketError(new Error(event.data || 'Unexpected WebSocket error'));
  };
  self.socket.onmessage = function (event) {
    var obj = {};
    try {
      obj = JSON.parse(event.data);
    } catch (e) {
      self.emit(new Error('Expected JSON-formatted WebSocket message'));
    }

    if (obj.type === 'data') {
      self.emit('data', obj.data);
    } else {
      self.emit(obj.type, obj.data);
    }
  };
  self.socket.onclose = function () {
    self.socketConnected = false;
    self._debug('close');

    if (self.reconnect) {
      var delay = self._calcReconnectTimeout(self._connections.socket.attempt);
      clearTimeout(self._socketReconnectDelayTimeout);
      self._socketReconnectDelayTimeout = setTimeout(function () {
        self.connect();
      }, delay);
    }
  };

  self.emit('connect_attempt');
  if (self._connections.socket.success > 0) {
    self.emit('reconnect_attempt');
  }
};

SocketPeer.prototype._socketError = function (err) {
  var self = this;
  self._connections.socket.error++;
  self.emit('error', err);
  self.emit('connect_error', err);
  if (self._connections.socket.success > 0) {
    self.emit('reconnect_error');
  }
};

SocketPeer.prototype._calcReconnectTimeout = function (attempts) {
  var self = this;
  return Math.min(Math.pow(2, attempts) * self.reconnectDelay, 30000);
};

SocketPeer.prototype._rtcInit = function () {
  var self = this;

  if (self.rtcConnected) {
    console.warn('WebRTC peer already connected');
    return;
  }

  self.peer = new SimplePeer({
    initiator: self.initiator,
    stream: self.stream
  });

  self.peer.on('connect', function () {
    clearTimeout(self._rtcReconnectTimeout);
    self._connections.rtc.success++;
    self._connections.rtc.attempt = 0;
    self.rtcConnected = true;
    self.emit('upgrade');
  });

  self.peer.on('stream', function (stream) {
    self.emit('stream', stream);
  });

  self.peer.on('error', function (err) {
    self._connections.rtc.error++;
    self.emit('upgrade_error', err);
    self.emit('error', err);
  });

  self.peer.on('signal', function (data) {
    if (self.rtcConnected) {
      return;
    }
    self._send('rtc.signal', data);
  });

  self.peer.on('data', function (data) {
    self.emit('data', data);
  });

  self.peer.on('close', function (data) {
    self.destroyPeer();

    if (self.socketConnected) {
      // NOTE: Currently the server does nothing with this message.
      // self._send('rtc.close', {pairCode: self.pairCode});

      if (self.reconnect && self.initiator) {
        var delay = self._calcReconnectTimeout(self._connections.rtc.attempt);
        clearTimeout(self._rtcReconnectTimeout);
        self._rtcReconnectTimeout = setTimeout(function () {
          self._send('rtc.connect');
          self._rtcInit();
        }, delay);
      }
    }

    self.emit('downgrade');
  });

  self._connections.rtc.attempt++;
  self.emit('upgrade_attempt');
};

SocketPeer.prototype._rtcSignal = function (data) {
  var self = this;
  if (!self.rtcConnected && self.peer && !self.peer.destroyed) {
    self.peer.signal(data);
  }
};

SocketPeer.prototype._send = function (type, data) {
  var self = this;
  if (!self.socket) {
    console.warn('Attempted to send message when socket was closed: %s', type);
    return;
  }
  data = JSON.stringify({
    type: type,
    data: data
  });
  self._debug('_send', data);
  self.socket.send(data);
};

SocketPeer.prototype.send = function (data) {
  var self = this;
  if (self.rtcConnected) {
    self.peer.send(data);
  } else {
    self._send('data', data);
  }
};

SocketPeer.prototype.close = function () {
  var self = this;
  self.destroyPeer();
  if (self.socket) {
    self.socket.close();
  }
};

SocketPeer.prototype.destroy = function () {
  var self = this;
  self.reconnect = false;
  self.close();
  self.peer = null;
  self.socket = null;
  self.socketConnected = false;
  self.rtcConnected = false;
  clearTimeout(self._socketConnectTimeout);
  clearTimeout(self._socketReconnectDelayTimeout);
  clearTimeout(self._rtcReconnectTimeout);
};

SocketPeer.prototype.destroyPeer = function () {
  var self = this;
  if (self.peer) {
    self.peer.destroy();
  }
  self.peer = null;
  self.rtcConnected = false;
};

SocketPeer.prototype._debug = function () {
  var self = this;
  if (self.debug) {
    var args = Array.prototype.slice.call(arguments);
    args[0] = '[' + self.pairCode + '] ' + args[0];
    console.log.apply(console, args);
  }
};

module.exports = SocketPeer;

},{"events":7,"inherits":10,"simple-peer":17,"xtend/mutable":34}],1:[function(require,module,exports){
var lookup = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

;(function (exports) {
	'use strict';

  var Arr = (typeof Uint8Array !== 'undefined')
    ? Uint8Array
    : Array

	var PLUS   = '+'.charCodeAt(0)
	var SLASH  = '/'.charCodeAt(0)
	var NUMBER = '0'.charCodeAt(0)
	var LOWER  = 'a'.charCodeAt(0)
	var UPPER  = 'A'.charCodeAt(0)
	var PLUS_URL_SAFE = '-'.charCodeAt(0)
	var SLASH_URL_SAFE = '_'.charCodeAt(0)

	function decode (elt) {
		var code = elt.charCodeAt(0)
		if (code === PLUS ||
		    code === PLUS_URL_SAFE)
			return 62 // '+'
		if (code === SLASH ||
		    code === SLASH_URL_SAFE)
			return 63 // '/'
		if (code < NUMBER)
			return -1 //no match
		if (code < NUMBER + 10)
			return code - NUMBER + 26 + 26
		if (code < UPPER + 26)
			return code - UPPER
		if (code < LOWER + 26)
			return code - LOWER + 26
	}

	function b64ToByteArray (b64) {
		var i, j, l, tmp, placeHolders, arr

		if (b64.length % 4 > 0) {
			throw new Error('Invalid string. Length must be a multiple of 4')
		}

		// the number of equal signs (place holders)
		// if there are two placeholders, than the two characters before it
		// represent one byte
		// if there is only one, then the three characters before it represent 2 bytes
		// this is just a cheap hack to not do indexOf twice
		var len = b64.length
		placeHolders = '=' === b64.charAt(len - 2) ? 2 : '=' === b64.charAt(len - 1) ? 1 : 0

		// base64 is 4/3 + up to two characters of the original data
		arr = new Arr(b64.length * 3 / 4 - placeHolders)

		// if there are placeholders, only get up to the last complete 4 chars
		l = placeHolders > 0 ? b64.length - 4 : b64.length

		var L = 0

		function push (v) {
			arr[L++] = v
		}

		for (i = 0, j = 0; i < l; i += 4, j += 3) {
			tmp = (decode(b64.charAt(i)) << 18) | (decode(b64.charAt(i + 1)) << 12) | (decode(b64.charAt(i + 2)) << 6) | decode(b64.charAt(i + 3))
			push((tmp & 0xFF0000) >> 16)
			push((tmp & 0xFF00) >> 8)
			push(tmp & 0xFF)
		}

		if (placeHolders === 2) {
			tmp = (decode(b64.charAt(i)) << 2) | (decode(b64.charAt(i + 1)) >> 4)
			push(tmp & 0xFF)
		} else if (placeHolders === 1) {
			tmp = (decode(b64.charAt(i)) << 10) | (decode(b64.charAt(i + 1)) << 4) | (decode(b64.charAt(i + 2)) >> 2)
			push((tmp >> 8) & 0xFF)
			push(tmp & 0xFF)
		}

		return arr
	}

	function uint8ToBase64 (uint8) {
		var i,
			extraBytes = uint8.length % 3, // if we have 1 byte left, pad 2 bytes
			output = "",
			temp, length

		function encode (num) {
			return lookup.charAt(num)
		}

		function tripletToBase64 (num) {
			return encode(num >> 18 & 0x3F) + encode(num >> 12 & 0x3F) + encode(num >> 6 & 0x3F) + encode(num & 0x3F)
		}

		// go through the array every three bytes, we'll deal with trailing stuff later
		for (i = 0, length = uint8.length - extraBytes; i < length; i += 3) {
			temp = (uint8[i] << 16) + (uint8[i + 1] << 8) + (uint8[i + 2])
			output += tripletToBase64(temp)
		}

		// pad the end with zeros, but make sure to not forget the extra bytes
		switch (extraBytes) {
			case 1:
				temp = uint8[uint8.length - 1]
				output += encode(temp >> 2)
				output += encode((temp << 4) & 0x3F)
				output += '=='
				break
			case 2:
				temp = (uint8[uint8.length - 2] << 8) + (uint8[uint8.length - 1])
				output += encode(temp >> 10)
				output += encode((temp >> 4) & 0x3F)
				output += encode((temp << 2) & 0x3F)
				output += '='
				break
		}

		return output
	}

	exports.toByteArray = b64ToByteArray
	exports.fromByteArray = uint8ToBase64
}(typeof exports === 'undefined' ? (this.base64js = {}) : exports))

},{}],2:[function(require,module,exports){

},{}],3:[function(require,module,exports){
(function (global){
/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * @license  MIT
 */
/* eslint-disable no-proto */

'use strict'

var base64 = require('base64-js')
var ieee754 = require('ieee754')
var isArray = require('isarray')

exports.Buffer = Buffer
exports.SlowBuffer = SlowBuffer
exports.INSPECT_MAX_BYTES = 50
Buffer.poolSize = 8192 // not used by this implementation

var rootParent = {}

/**
 * If `Buffer.TYPED_ARRAY_SUPPORT`:
 *   === true    Use Uint8Array implementation (fastest)
 *   === false   Use Object implementation (most compatible, even IE6)
 *
 * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
 * Opera 11.6+, iOS 4.2+.
 *
 * Due to various browser bugs, sometimes the Object implementation will be used even
 * when the browser supports typed arrays.
 *
 * Note:
 *
 *   - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances,
 *     See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438.
 *
 *   - Safari 5-7 lacks support for changing the `Object.prototype.constructor` property
 *     on objects.
 *
 *   - Chrome 9-10 is missing the `TypedArray.prototype.subarray` function.
 *
 *   - IE10 has a broken `TypedArray.prototype.subarray` function which returns arrays of
 *     incorrect length in some situations.

 * We detect these buggy browsers and set `Buffer.TYPED_ARRAY_SUPPORT` to `false` so they
 * get the Object implementation, which is slower but behaves correctly.
 */
Buffer.TYPED_ARRAY_SUPPORT = global.TYPED_ARRAY_SUPPORT !== undefined
  ? global.TYPED_ARRAY_SUPPORT
  : typedArraySupport()

function typedArraySupport () {
  function Bar () {}
  try {
    var arr = new Uint8Array(1)
    arr.foo = function () { return 42 }
    arr.constructor = Bar
    return arr.foo() === 42 && // typed array instances can be augmented
        arr.constructor === Bar && // constructor can be set
        typeof arr.subarray === 'function' && // chrome 9-10 lack `subarray`
        arr.subarray(1, 1).byteLength === 0 // ie10 has broken `subarray`
  } catch (e) {
    return false
  }
}

function kMaxLength () {
  return Buffer.TYPED_ARRAY_SUPPORT
    ? 0x7fffffff
    : 0x3fffffff
}

/**
 * Class: Buffer
 * =============
 *
 * The Buffer constructor returns instances of `Uint8Array` that are augmented
 * with function properties for all the node `Buffer` API functions. We use
 * `Uint8Array` so that square bracket notation works as expected -- it returns
 * a single octet.
 *
 * By augmenting the instances, we can avoid modifying the `Uint8Array`
 * prototype.
 */
function Buffer (arg) {
  if (!(this instanceof Buffer)) {
    // Avoid going through an ArgumentsAdaptorTrampoline in the common case.
    if (arguments.length > 1) return new Buffer(arg, arguments[1])
    return new Buffer(arg)
  }

  if (!Buffer.TYPED_ARRAY_SUPPORT) {
    this.length = 0
    this.parent = undefined
  }

  // Common case.
  if (typeof arg === 'number') {
    return fromNumber(this, arg)
  }

  // Slightly less common case.
  if (typeof arg === 'string') {
    return fromString(this, arg, arguments.length > 1 ? arguments[1] : 'utf8')
  }

  // Unusual.
  return fromObject(this, arg)
}

function fromNumber (that, length) {
  that = allocate(that, length < 0 ? 0 : checked(length) | 0)
  if (!Buffer.TYPED_ARRAY_SUPPORT) {
    for (var i = 0; i < length; i++) {
      that[i] = 0
    }
  }
  return that
}

function fromString (that, string, encoding) {
  if (typeof encoding !== 'string' || encoding === '') encoding = 'utf8'

  // Assumption: byteLength() return value is always < kMaxLength.
  var length = byteLength(string, encoding) | 0
  that = allocate(that, length)

  that.write(string, encoding)
  return that
}

function fromObject (that, object) {
  if (Buffer.isBuffer(object)) return fromBuffer(that, object)

  if (isArray(object)) return fromArray(that, object)

  if (object == null) {
    throw new TypeError('must start with number, buffer, array or string')
  }

  if (typeof ArrayBuffer !== 'undefined') {
    if (object.buffer instanceof ArrayBuffer) {
      return fromTypedArray(that, object)
    }
    if (object instanceof ArrayBuffer) {
      return fromArrayBuffer(that, object)
    }
  }

  if (object.length) return fromArrayLike(that, object)

  return fromJsonObject(that, object)
}

function fromBuffer (that, buffer) {
  var length = checked(buffer.length) | 0
  that = allocate(that, length)
  buffer.copy(that, 0, 0, length)
  return that
}

function fromArray (that, array) {
  var length = checked(array.length) | 0
  that = allocate(that, length)
  for (var i = 0; i < length; i += 1) {
    that[i] = array[i] & 255
  }
  return that
}

// Duplicate of fromArray() to keep fromArray() monomorphic.
function fromTypedArray (that, array) {
  var length = checked(array.length) | 0
  that = allocate(that, length)
  // Truncating the elements is probably not what people expect from typed
  // arrays with BYTES_PER_ELEMENT > 1 but it's compatible with the behavior
  // of the old Buffer constructor.
  for (var i = 0; i < length; i += 1) {
    that[i] = array[i] & 255
  }
  return that
}

function fromArrayBuffer (that, array) {
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    // Return an augmented `Uint8Array` instance, for best performance
    array.byteLength
    that = Buffer._augment(new Uint8Array(array))
  } else {
    // Fallback: Return an object instance of the Buffer class
    that = fromTypedArray(that, new Uint8Array(array))
  }
  return that
}

function fromArrayLike (that, array) {
  var length = checked(array.length) | 0
  that = allocate(that, length)
  for (var i = 0; i < length; i += 1) {
    that[i] = array[i] & 255
  }
  return that
}

// Deserialize { type: 'Buffer', data: [1,2,3,...] } into a Buffer object.
// Returns a zero-length buffer for inputs that don't conform to the spec.
function fromJsonObject (that, object) {
  var array
  var length = 0

  if (object.type === 'Buffer' && isArray(object.data)) {
    array = object.data
    length = checked(array.length) | 0
  }
  that = allocate(that, length)

  for (var i = 0; i < length; i += 1) {
    that[i] = array[i] & 255
  }
  return that
}

if (Buffer.TYPED_ARRAY_SUPPORT) {
  Buffer.prototype.__proto__ = Uint8Array.prototype
  Buffer.__proto__ = Uint8Array
} else {
  // pre-set for values that may exist in the future
  Buffer.prototype.length = undefined
  Buffer.prototype.parent = undefined
}

function allocate (that, length) {
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    // Return an augmented `Uint8Array` instance, for best performance
    that = Buffer._augment(new Uint8Array(length))
    that.__proto__ = Buffer.prototype
  } else {
    // Fallback: Return an object instance of the Buffer class
    that.length = length
    that._isBuffer = true
  }

  var fromPool = length !== 0 && length <= Buffer.poolSize >>> 1
  if (fromPool) that.parent = rootParent

  return that
}

function checked (length) {
  // Note: cannot use `length < kMaxLength` here because that fails when
  // length is NaN (which is otherwise coerced to zero.)
  if (length >= kMaxLength()) {
    throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
                         'size: 0x' + kMaxLength().toString(16) + ' bytes')
  }
  return length | 0
}

function SlowBuffer (subject, encoding) {
  if (!(this instanceof SlowBuffer)) return new SlowBuffer(subject, encoding)

  var buf = new Buffer(subject, encoding)
  delete buf.parent
  return buf
}

Buffer.isBuffer = function isBuffer (b) {
  return !!(b != null && b._isBuffer)
}

Buffer.compare = function compare (a, b) {
  if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
    throw new TypeError('Arguments must be Buffers')
  }

  if (a === b) return 0

  var x = a.length
  var y = b.length

  var i = 0
  var len = Math.min(x, y)
  while (i < len) {
    if (a[i] !== b[i]) break

    ++i
  }

  if (i !== len) {
    x = a[i]
    y = b[i]
  }

  if (x < y) return -1
  if (y < x) return 1
  return 0
}

Buffer.isEncoding = function isEncoding (encoding) {
  switch (String(encoding).toLowerCase()) {
    case 'hex':
    case 'utf8':
    case 'utf-8':
    case 'ascii':
    case 'binary':
    case 'base64':
    case 'raw':
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      return true
    default:
      return false
  }
}

Buffer.concat = function concat (list, length) {
  if (!isArray(list)) throw new TypeError('list argument must be an Array of Buffers.')

  if (list.length === 0) {
    return new Buffer(0)
  }

  var i
  if (length === undefined) {
    length = 0
    for (i = 0; i < list.length; i++) {
      length += list[i].length
    }
  }

  var buf = new Buffer(length)
  var pos = 0
  for (i = 0; i < list.length; i++) {
    var item = list[i]
    item.copy(buf, pos)
    pos += item.length
  }
  return buf
}

function byteLength (string, encoding) {
  if (typeof string !== 'string') string = '' + string

  var len = string.length
  if (len === 0) return 0

  // Use a for loop to avoid recursion
  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'ascii':
      case 'binary':
      // Deprecated
      case 'raw':
      case 'raws':
        return len
      case 'utf8':
      case 'utf-8':
        return utf8ToBytes(string).length
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return len * 2
      case 'hex':
        return len >>> 1
      case 'base64':
        return base64ToBytes(string).length
      default:
        if (loweredCase) return utf8ToBytes(string).length // assume utf8
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}
Buffer.byteLength = byteLength

function slowToString (encoding, start, end) {
  var loweredCase = false

  start = start | 0
  end = end === undefined || end === Infinity ? this.length : end | 0

  if (!encoding) encoding = 'utf8'
  if (start < 0) start = 0
  if (end > this.length) end = this.length
  if (end <= start) return ''

  while (true) {
    switch (encoding) {
      case 'hex':
        return hexSlice(this, start, end)

      case 'utf8':
      case 'utf-8':
        return utf8Slice(this, start, end)

      case 'ascii':
        return asciiSlice(this, start, end)

      case 'binary':
        return binarySlice(this, start, end)

      case 'base64':
        return base64Slice(this, start, end)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return utf16leSlice(this, start, end)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = (encoding + '').toLowerCase()
        loweredCase = true
    }
  }
}

Buffer.prototype.toString = function toString () {
  var length = this.length | 0
  if (length === 0) return ''
  if (arguments.length === 0) return utf8Slice(this, 0, length)
  return slowToString.apply(this, arguments)
}

Buffer.prototype.equals = function equals (b) {
  if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
  if (this === b) return true
  return Buffer.compare(this, b) === 0
}

Buffer.prototype.inspect = function inspect () {
  var str = ''
  var max = exports.INSPECT_MAX_BYTES
  if (this.length > 0) {
    str = this.toString('hex', 0, max).match(/.{2}/g).join(' ')
    if (this.length > max) str += ' ... '
  }
  return '<Buffer ' + str + '>'
}

Buffer.prototype.compare = function compare (b) {
  if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
  if (this === b) return 0
  return Buffer.compare(this, b)
}

Buffer.prototype.indexOf = function indexOf (val, byteOffset) {
  if (byteOffset > 0x7fffffff) byteOffset = 0x7fffffff
  else if (byteOffset < -0x80000000) byteOffset = -0x80000000
  byteOffset >>= 0

  if (this.length === 0) return -1
  if (byteOffset >= this.length) return -1

  // Negative offsets start from the end of the buffer
  if (byteOffset < 0) byteOffset = Math.max(this.length + byteOffset, 0)

  if (typeof val === 'string') {
    if (val.length === 0) return -1 // special case: looking for empty string always fails
    return String.prototype.indexOf.call(this, val, byteOffset)
  }
  if (Buffer.isBuffer(val)) {
    return arrayIndexOf(this, val, byteOffset)
  }
  if (typeof val === 'number') {
    if (Buffer.TYPED_ARRAY_SUPPORT && Uint8Array.prototype.indexOf === 'function') {
      return Uint8Array.prototype.indexOf.call(this, val, byteOffset)
    }
    return arrayIndexOf(this, [ val ], byteOffset)
  }

  function arrayIndexOf (arr, val, byteOffset) {
    var foundIndex = -1
    for (var i = 0; byteOffset + i < arr.length; i++) {
      if (arr[byteOffset + i] === val[foundIndex === -1 ? 0 : i - foundIndex]) {
        if (foundIndex === -1) foundIndex = i
        if (i - foundIndex + 1 === val.length) return byteOffset + foundIndex
      } else {
        foundIndex = -1
      }
    }
    return -1
  }

  throw new TypeError('val must be string, number or Buffer')
}

// `get` is deprecated
Buffer.prototype.get = function get (offset) {
  console.log('.get() is deprecated. Access using array indexes instead.')
  return this.readUInt8(offset)
}

// `set` is deprecated
Buffer.prototype.set = function set (v, offset) {
  console.log('.set() is deprecated. Access using array indexes instead.')
  return this.writeUInt8(v, offset)
}

function hexWrite (buf, string, offset, length) {
  offset = Number(offset) || 0
  var remaining = buf.length - offset
  if (!length) {
    length = remaining
  } else {
    length = Number(length)
    if (length > remaining) {
      length = remaining
    }
  }

  // must be an even number of digits
  var strLen = string.length
  if (strLen % 2 !== 0) throw new Error('Invalid hex string')

  if (length > strLen / 2) {
    length = strLen / 2
  }
  for (var i = 0; i < length; i++) {
    var parsed = parseInt(string.substr(i * 2, 2), 16)
    if (isNaN(parsed)) throw new Error('Invalid hex string')
    buf[offset + i] = parsed
  }
  return i
}

function utf8Write (buf, string, offset, length) {
  return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
}

function asciiWrite (buf, string, offset, length) {
  return blitBuffer(asciiToBytes(string), buf, offset, length)
}

function binaryWrite (buf, string, offset, length) {
  return asciiWrite(buf, string, offset, length)
}

function base64Write (buf, string, offset, length) {
  return blitBuffer(base64ToBytes(string), buf, offset, length)
}

function ucs2Write (buf, string, offset, length) {
  return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
}

Buffer.prototype.write = function write (string, offset, length, encoding) {
  // Buffer#write(string)
  if (offset === undefined) {
    encoding = 'utf8'
    length = this.length
    offset = 0
  // Buffer#write(string, encoding)
  } else if (length === undefined && typeof offset === 'string') {
    encoding = offset
    length = this.length
    offset = 0
  // Buffer#write(string, offset[, length][, encoding])
  } else if (isFinite(offset)) {
    offset = offset | 0
    if (isFinite(length)) {
      length = length | 0
      if (encoding === undefined) encoding = 'utf8'
    } else {
      encoding = length
      length = undefined
    }
  // legacy write(string, encoding, offset, length) - remove in v0.13
  } else {
    var swap = encoding
    encoding = offset
    offset = length | 0
    length = swap
  }

  var remaining = this.length - offset
  if (length === undefined || length > remaining) length = remaining

  if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
    throw new RangeError('attempt to write outside buffer bounds')
  }

  if (!encoding) encoding = 'utf8'

  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'hex':
        return hexWrite(this, string, offset, length)

      case 'utf8':
      case 'utf-8':
        return utf8Write(this, string, offset, length)

      case 'ascii':
        return asciiWrite(this, string, offset, length)

      case 'binary':
        return binaryWrite(this, string, offset, length)

      case 'base64':
        // Warning: maxLength not taken into account in base64Write
        return base64Write(this, string, offset, length)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return ucs2Write(this, string, offset, length)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}

Buffer.prototype.toJSON = function toJSON () {
  return {
    type: 'Buffer',
    data: Array.prototype.slice.call(this._arr || this, 0)
  }
}

function base64Slice (buf, start, end) {
  if (start === 0 && end === buf.length) {
    return base64.fromByteArray(buf)
  } else {
    return base64.fromByteArray(buf.slice(start, end))
  }
}

function utf8Slice (buf, start, end) {
  end = Math.min(buf.length, end)
  var res = []

  var i = start
  while (i < end) {
    var firstByte = buf[i]
    var codePoint = null
    var bytesPerSequence = (firstByte > 0xEF) ? 4
      : (firstByte > 0xDF) ? 3
      : (firstByte > 0xBF) ? 2
      : 1

    if (i + bytesPerSequence <= end) {
      var secondByte, thirdByte, fourthByte, tempCodePoint

      switch (bytesPerSequence) {
        case 1:
          if (firstByte < 0x80) {
            codePoint = firstByte
          }
          break
        case 2:
          secondByte = buf[i + 1]
          if ((secondByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
            if (tempCodePoint > 0x7F) {
              codePoint = tempCodePoint
            }
          }
          break
        case 3:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
            if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
              codePoint = tempCodePoint
            }
          }
          break
        case 4:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          fourthByte = buf[i + 3]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
            if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
              codePoint = tempCodePoint
            }
          }
      }
    }

    if (codePoint === null) {
      // we did not generate a valid codePoint so insert a
      // replacement char (U+FFFD) and advance only 1 byte
      codePoint = 0xFFFD
      bytesPerSequence = 1
    } else if (codePoint > 0xFFFF) {
      // encode to utf16 (surrogate pair dance)
      codePoint -= 0x10000
      res.push(codePoint >>> 10 & 0x3FF | 0xD800)
      codePoint = 0xDC00 | codePoint & 0x3FF
    }

    res.push(codePoint)
    i += bytesPerSequence
  }

  return decodeCodePointsArray(res)
}

// Based on http://stackoverflow.com/a/22747272/680742, the browser with
// the lowest limit is Chrome, with 0x10000 args.
// We go 1 magnitude less, for safety
var MAX_ARGUMENTS_LENGTH = 0x1000

function decodeCodePointsArray (codePoints) {
  var len = codePoints.length
  if (len <= MAX_ARGUMENTS_LENGTH) {
    return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
  }

  // Decode in chunks to avoid "call stack size exceeded".
  var res = ''
  var i = 0
  while (i < len) {
    res += String.fromCharCode.apply(
      String,
      codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
    )
  }
  return res
}

function asciiSlice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; i++) {
    ret += String.fromCharCode(buf[i] & 0x7F)
  }
  return ret
}

function binarySlice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; i++) {
    ret += String.fromCharCode(buf[i])
  }
  return ret
}

function hexSlice (buf, start, end) {
  var len = buf.length

  if (!start || start < 0) start = 0
  if (!end || end < 0 || end > len) end = len

  var out = ''
  for (var i = start; i < end; i++) {
    out += toHex(buf[i])
  }
  return out
}

function utf16leSlice (buf, start, end) {
  var bytes = buf.slice(start, end)
  var res = ''
  for (var i = 0; i < bytes.length; i += 2) {
    res += String.fromCharCode(bytes[i] + bytes[i + 1] * 256)
  }
  return res
}

Buffer.prototype.slice = function slice (start, end) {
  var len = this.length
  start = ~~start
  end = end === undefined ? len : ~~end

  if (start < 0) {
    start += len
    if (start < 0) start = 0
  } else if (start > len) {
    start = len
  }

  if (end < 0) {
    end += len
    if (end < 0) end = 0
  } else if (end > len) {
    end = len
  }

  if (end < start) end = start

  var newBuf
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    newBuf = Buffer._augment(this.subarray(start, end))
  } else {
    var sliceLen = end - start
    newBuf = new Buffer(sliceLen, undefined)
    for (var i = 0; i < sliceLen; i++) {
      newBuf[i] = this[i + start]
    }
  }

  if (newBuf.length) newBuf.parent = this.parent || this

  return newBuf
}

/*
 * Need to make sure that buffer isn't trying to write out of bounds.
 */
function checkOffset (offset, ext, length) {
  if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
  if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
}

Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }

  return val
}

Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) {
    checkOffset(offset, byteLength, this.length)
  }

  var val = this[offset + --byteLength]
  var mul = 1
  while (byteLength > 0 && (mul *= 0x100)) {
    val += this[offset + --byteLength] * mul
  }

  return val
}

Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 1, this.length)
  return this[offset]
}

Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 2, this.length)
  return this[offset] | (this[offset + 1] << 8)
}

Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 2, this.length)
  return (this[offset] << 8) | this[offset + 1]
}

Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)

  return ((this[offset]) |
      (this[offset + 1] << 8) |
      (this[offset + 2] << 16)) +
      (this[offset + 3] * 0x1000000)
}

Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset] * 0x1000000) +
    ((this[offset + 1] << 16) |
    (this[offset + 2] << 8) |
    this[offset + 3])
}

Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var i = byteLength
  var mul = 1
  var val = this[offset + --i]
  while (i > 0 && (mul *= 0x100)) {
    val += this[offset + --i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 1, this.length)
  if (!(this[offset] & 0x80)) return (this[offset])
  return ((0xff - this[offset] + 1) * -1)
}

Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset] | (this[offset + 1] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset + 1] | (this[offset] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset]) |
    (this[offset + 1] << 8) |
    (this[offset + 2] << 16) |
    (this[offset + 3] << 24)
}

Buffer.prototype.readInt32BE = function readInt32BE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset] << 24) |
    (this[offset + 1] << 16) |
    (this[offset + 2] << 8) |
    (this[offset + 3])
}

Buffer.prototype.readFloatLE = function readFloatLE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)
  return ieee754.read(this, offset, true, 23, 4)
}

Buffer.prototype.readFloatBE = function readFloatBE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 4, this.length)
  return ieee754.read(this, offset, false, 23, 4)
}

Buffer.prototype.readDoubleLE = function readDoubleLE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 8, this.length)
  return ieee754.read(this, offset, true, 52, 8)
}

Buffer.prototype.readDoubleBE = function readDoubleBE (offset, noAssert) {
  if (!noAssert) checkOffset(offset, 8, this.length)
  return ieee754.read(this, offset, false, 52, 8)
}

function checkInt (buf, value, offset, ext, max, min) {
  if (!Buffer.isBuffer(buf)) throw new TypeError('buffer must be a Buffer instance')
  if (value > max || value < min) throw new RangeError('value is out of bounds')
  if (offset + ext > buf.length) throw new RangeError('index out of range')
}

Buffer.prototype.writeUIntLE = function writeUIntLE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength), 0)

  var mul = 1
  var i = 0
  this[offset] = value & 0xFF
  while (++i < byteLength && (mul *= 0x100)) {
    this[offset + i] = (value / mul) & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeUIntBE = function writeUIntBE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset | 0
  byteLength = byteLength | 0
  if (!noAssert) checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength), 0)

  var i = byteLength - 1
  var mul = 1
  this[offset + i] = value & 0xFF
  while (--i >= 0 && (mul *= 0x100)) {
    this[offset + i] = (value / mul) & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeUInt8 = function writeUInt8 (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0)
  if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value)
  this[offset] = (value & 0xff)
  return offset + 1
}

function objectWriteUInt16 (buf, value, offset, littleEndian) {
  if (value < 0) value = 0xffff + value + 1
  for (var i = 0, j = Math.min(buf.length - offset, 2); i < j; i++) {
    buf[offset + i] = (value & (0xff << (8 * (littleEndian ? i : 1 - i)))) >>>
      (littleEndian ? i : 1 - i) * 8
  }
}

Buffer.prototype.writeUInt16LE = function writeUInt16LE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
  } else {
    objectWriteUInt16(this, value, offset, true)
  }
  return offset + 2
}

Buffer.prototype.writeUInt16BE = function writeUInt16BE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
  } else {
    objectWriteUInt16(this, value, offset, false)
  }
  return offset + 2
}

function objectWriteUInt32 (buf, value, offset, littleEndian) {
  if (value < 0) value = 0xffffffff + value + 1
  for (var i = 0, j = Math.min(buf.length - offset, 4); i < j; i++) {
    buf[offset + i] = (value >>> (littleEndian ? i : 3 - i) * 8) & 0xff
  }
}

Buffer.prototype.writeUInt32LE = function writeUInt32LE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset + 3] = (value >>> 24)
    this[offset + 2] = (value >>> 16)
    this[offset + 1] = (value >>> 8)
    this[offset] = (value & 0xff)
  } else {
    objectWriteUInt32(this, value, offset, true)
  }
  return offset + 4
}

Buffer.prototype.writeUInt32BE = function writeUInt32BE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
  } else {
    objectWriteUInt32(this, value, offset, false)
  }
  return offset + 4
}

Buffer.prototype.writeIntLE = function writeIntLE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) {
    var limit = Math.pow(2, 8 * byteLength - 1)

    checkInt(this, value, offset, byteLength, limit - 1, -limit)
  }

  var i = 0
  var mul = 1
  var sub = value < 0 ? 1 : 0
  this[offset] = value & 0xFF
  while (++i < byteLength && (mul *= 0x100)) {
    this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeIntBE = function writeIntBE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) {
    var limit = Math.pow(2, 8 * byteLength - 1)

    checkInt(this, value, offset, byteLength, limit - 1, -limit)
  }

  var i = byteLength - 1
  var mul = 1
  var sub = value < 0 ? 1 : 0
  this[offset + i] = value & 0xFF
  while (--i >= 0 && (mul *= 0x100)) {
    this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeInt8 = function writeInt8 (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80)
  if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value)
  if (value < 0) value = 0xff + value + 1
  this[offset] = (value & 0xff)
  return offset + 1
}

Buffer.prototype.writeInt16LE = function writeInt16LE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
  } else {
    objectWriteUInt16(this, value, offset, true)
  }
  return offset + 2
}

Buffer.prototype.writeInt16BE = function writeInt16BE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
  } else {
    objectWriteUInt16(this, value, offset, false)
  }
  return offset + 2
}

Buffer.prototype.writeInt32LE = function writeInt32LE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    this[offset + 2] = (value >>> 16)
    this[offset + 3] = (value >>> 24)
  } else {
    objectWriteUInt32(this, value, offset, true)
  }
  return offset + 4
}

Buffer.prototype.writeInt32BE = function writeInt32BE (value, offset, noAssert) {
  value = +value
  offset = offset | 0
  if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
  if (value < 0) value = 0xffffffff + value + 1
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
  } else {
    objectWriteUInt32(this, value, offset, false)
  }
  return offset + 4
}

function checkIEEE754 (buf, value, offset, ext, max, min) {
  if (value > max || value < min) throw new RangeError('value is out of bounds')
  if (offset + ext > buf.length) throw new RangeError('index out of range')
  if (offset < 0) throw new RangeError('index out of range')
}

function writeFloat (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    checkIEEE754(buf, value, offset, 4, 3.4028234663852886e+38, -3.4028234663852886e+38)
  }
  ieee754.write(buf, value, offset, littleEndian, 23, 4)
  return offset + 4
}

Buffer.prototype.writeFloatLE = function writeFloatLE (value, offset, noAssert) {
  return writeFloat(this, value, offset, true, noAssert)
}

Buffer.prototype.writeFloatBE = function writeFloatBE (value, offset, noAssert) {
  return writeFloat(this, value, offset, false, noAssert)
}

function writeDouble (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    checkIEEE754(buf, value, offset, 8, 1.7976931348623157E+308, -1.7976931348623157E+308)
  }
  ieee754.write(buf, value, offset, littleEndian, 52, 8)
  return offset + 8
}

Buffer.prototype.writeDoubleLE = function writeDoubleLE (value, offset, noAssert) {
  return writeDouble(this, value, offset, true, noAssert)
}

Buffer.prototype.writeDoubleBE = function writeDoubleBE (value, offset, noAssert) {
  return writeDouble(this, value, offset, false, noAssert)
}

// copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
Buffer.prototype.copy = function copy (target, targetStart, start, end) {
  if (!start) start = 0
  if (!end && end !== 0) end = this.length
  if (targetStart >= target.length) targetStart = target.length
  if (!targetStart) targetStart = 0
  if (end > 0 && end < start) end = start

  // Copy 0 bytes; we're done
  if (end === start) return 0
  if (target.length === 0 || this.length === 0) return 0

  // Fatal error conditions
  if (targetStart < 0) {
    throw new RangeError('targetStart out of bounds')
  }
  if (start < 0 || start >= this.length) throw new RangeError('sourceStart out of bounds')
  if (end < 0) throw new RangeError('sourceEnd out of bounds')

  // Are we oob?
  if (end > this.length) end = this.length
  if (target.length - targetStart < end - start) {
    end = target.length - targetStart + start
  }

  var len = end - start
  var i

  if (this === target && start < targetStart && targetStart < end) {
    // descending copy from end
    for (i = len - 1; i >= 0; i--) {
      target[i + targetStart] = this[i + start]
    }
  } else if (len < 1000 || !Buffer.TYPED_ARRAY_SUPPORT) {
    // ascending copy from start
    for (i = 0; i < len; i++) {
      target[i + targetStart] = this[i + start]
    }
  } else {
    target._set(this.subarray(start, start + len), targetStart)
  }

  return len
}

// fill(value, start=0, end=buffer.length)
Buffer.prototype.fill = function fill (value, start, end) {
  if (!value) value = 0
  if (!start) start = 0
  if (!end) end = this.length

  if (end < start) throw new RangeError('end < start')

  // Fill 0 bytes; we're done
  if (end === start) return
  if (this.length === 0) return

  if (start < 0 || start >= this.length) throw new RangeError('start out of bounds')
  if (end < 0 || end > this.length) throw new RangeError('end out of bounds')

  var i
  if (typeof value === 'number') {
    for (i = start; i < end; i++) {
      this[i] = value
    }
  } else {
    var bytes = utf8ToBytes(value.toString())
    var len = bytes.length
    for (i = start; i < end; i++) {
      this[i] = bytes[i % len]
    }
  }

  return this
}

/**
 * Creates a new `ArrayBuffer` with the *copied* memory of the buffer instance.
 * Added in Node 0.12. Only available in browsers that support ArrayBuffer.
 */
Buffer.prototype.toArrayBuffer = function toArrayBuffer () {
  if (typeof Uint8Array !== 'undefined') {
    if (Buffer.TYPED_ARRAY_SUPPORT) {
      return (new Buffer(this)).buffer
    } else {
      var buf = new Uint8Array(this.length)
      for (var i = 0, len = buf.length; i < len; i += 1) {
        buf[i] = this[i]
      }
      return buf.buffer
    }
  } else {
    throw new TypeError('Buffer.toArrayBuffer not supported in this browser')
  }
}

// HELPER FUNCTIONS
// ================

var BP = Buffer.prototype

/**
 * Augment a Uint8Array *instance* (not the Uint8Array class!) with Buffer methods
 */
Buffer._augment = function _augment (arr) {
  arr.constructor = Buffer
  arr._isBuffer = true

  // save reference to original Uint8Array set method before overwriting
  arr._set = arr.set

  // deprecated
  arr.get = BP.get
  arr.set = BP.set

  arr.write = BP.write
  arr.toString = BP.toString
  arr.toLocaleString = BP.toString
  arr.toJSON = BP.toJSON
  arr.equals = BP.equals
  arr.compare = BP.compare
  arr.indexOf = BP.indexOf
  arr.copy = BP.copy
  arr.slice = BP.slice
  arr.readUIntLE = BP.readUIntLE
  arr.readUIntBE = BP.readUIntBE
  arr.readUInt8 = BP.readUInt8
  arr.readUInt16LE = BP.readUInt16LE
  arr.readUInt16BE = BP.readUInt16BE
  arr.readUInt32LE = BP.readUInt32LE
  arr.readUInt32BE = BP.readUInt32BE
  arr.readIntLE = BP.readIntLE
  arr.readIntBE = BP.readIntBE
  arr.readInt8 = BP.readInt8
  arr.readInt16LE = BP.readInt16LE
  arr.readInt16BE = BP.readInt16BE
  arr.readInt32LE = BP.readInt32LE
  arr.readInt32BE = BP.readInt32BE
  arr.readFloatLE = BP.readFloatLE
  arr.readFloatBE = BP.readFloatBE
  arr.readDoubleLE = BP.readDoubleLE
  arr.readDoubleBE = BP.readDoubleBE
  arr.writeUInt8 = BP.writeUInt8
  arr.writeUIntLE = BP.writeUIntLE
  arr.writeUIntBE = BP.writeUIntBE
  arr.writeUInt16LE = BP.writeUInt16LE
  arr.writeUInt16BE = BP.writeUInt16BE
  arr.writeUInt32LE = BP.writeUInt32LE
  arr.writeUInt32BE = BP.writeUInt32BE
  arr.writeIntLE = BP.writeIntLE
  arr.writeIntBE = BP.writeIntBE
  arr.writeInt8 = BP.writeInt8
  arr.writeInt16LE = BP.writeInt16LE
  arr.writeInt16BE = BP.writeInt16BE
  arr.writeInt32LE = BP.writeInt32LE
  arr.writeInt32BE = BP.writeInt32BE
  arr.writeFloatLE = BP.writeFloatLE
  arr.writeFloatBE = BP.writeFloatBE
  arr.writeDoubleLE = BP.writeDoubleLE
  arr.writeDoubleBE = BP.writeDoubleBE
  arr.fill = BP.fill
  arr.inspect = BP.inspect
  arr.toArrayBuffer = BP.toArrayBuffer

  return arr
}

var INVALID_BASE64_RE = /[^+\/0-9A-Za-z-_]/g

function base64clean (str) {
  // Node strips out invalid characters like \n and \t from the string, base64-js does not
  str = stringtrim(str).replace(INVALID_BASE64_RE, '')
  // Node converts strings with length < 2 to ''
  if (str.length < 2) return ''
  // Node allows for non-padded base64 strings (missing trailing ===), base64-js does not
  while (str.length % 4 !== 0) {
    str = str + '='
  }
  return str
}

function stringtrim (str) {
  if (str.trim) return str.trim()
  return str.replace(/^\s+|\s+$/g, '')
}

function toHex (n) {
  if (n < 16) return '0' + n.toString(16)
  return n.toString(16)
}

function utf8ToBytes (string, units) {
  units = units || Infinity
  var codePoint
  var length = string.length
  var leadSurrogate = null
  var bytes = []

  for (var i = 0; i < length; i++) {
    codePoint = string.charCodeAt(i)

    // is surrogate component
    if (codePoint > 0xD7FF && codePoint < 0xE000) {
      // last char was a lead
      if (!leadSurrogate) {
        // no lead yet
        if (codePoint > 0xDBFF) {
          // unexpected trail
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          continue
        } else if (i + 1 === length) {
          // unpaired lead
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          continue
        }

        // valid lead
        leadSurrogate = codePoint

        continue
      }

      // 2 leads in a row
      if (codePoint < 0xDC00) {
        if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
        leadSurrogate = codePoint
        continue
      }

      // valid surrogate pair
      codePoint = (leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00) + 0x10000
    } else if (leadSurrogate) {
      // valid bmp char, but last char was a lead
      if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
    }

    leadSurrogate = null

    // encode utf8
    if (codePoint < 0x80) {
      if ((units -= 1) < 0) break
      bytes.push(codePoint)
    } else if (codePoint < 0x800) {
      if ((units -= 2) < 0) break
      bytes.push(
        codePoint >> 0x6 | 0xC0,
        codePoint & 0x3F | 0x80
      )
    } else if (codePoint < 0x10000) {
      if ((units -= 3) < 0) break
      bytes.push(
        codePoint >> 0xC | 0xE0,
        codePoint >> 0x6 & 0x3F | 0x80,
        codePoint & 0x3F | 0x80
      )
    } else if (codePoint < 0x110000) {
      if ((units -= 4) < 0) break
      bytes.push(
        codePoint >> 0x12 | 0xF0,
        codePoint >> 0xC & 0x3F | 0x80,
        codePoint >> 0x6 & 0x3F | 0x80,
        codePoint & 0x3F | 0x80
      )
    } else {
      throw new Error('Invalid code point')
    }
  }

  return bytes
}

function asciiToBytes (str) {
  var byteArray = []
  for (var i = 0; i < str.length; i++) {
    // Node's code seems to be doing this and not & 0x7F..
    byteArray.push(str.charCodeAt(i) & 0xFF)
  }
  return byteArray
}

function utf16leToBytes (str, units) {
  var c, hi, lo
  var byteArray = []
  for (var i = 0; i < str.length; i++) {
    if ((units -= 2) < 0) break

    c = str.charCodeAt(i)
    hi = c >> 8
    lo = c % 256
    byteArray.push(lo)
    byteArray.push(hi)
  }

  return byteArray
}

function base64ToBytes (str) {
  return base64.toByteArray(base64clean(str))
}

function blitBuffer (src, dst, offset, length) {
  for (var i = 0; i < length; i++) {
    if ((i + offset >= dst.length) || (i >= src.length)) break
    dst[i + offset] = src[i]
  }
  return i
}

}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"base64-js":1,"ieee754":9,"isarray":13}],4:[function(require,module,exports){
(function (Buffer){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// NOTE: These type checking functions intentionally don't use `instanceof`
// because it is fragile and can be easily faked with `Object.create()`.

function isArray(arg) {
  if (Array.isArray) {
    return Array.isArray(arg);
  }
  return objectToString(arg) === '[object Array]';
}
exports.isArray = isArray;

function isBoolean(arg) {
  return typeof arg === 'boolean';
}
exports.isBoolean = isBoolean;

function isNull(arg) {
  return arg === null;
}
exports.isNull = isNull;

function isNullOrUndefined(arg) {
  return arg == null;
}
exports.isNullOrUndefined = isNullOrUndefined;

function isNumber(arg) {
  return typeof arg === 'number';
}
exports.isNumber = isNumber;

function isString(arg) {
  return typeof arg === 'string';
}
exports.isString = isString;

function isSymbol(arg) {
  return typeof arg === 'symbol';
}
exports.isSymbol = isSymbol;

function isUndefined(arg) {
  return arg === void 0;
}
exports.isUndefined = isUndefined;

function isRegExp(re) {
  return objectToString(re) === '[object RegExp]';
}
exports.isRegExp = isRegExp;

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}
exports.isObject = isObject;

function isDate(d) {
  return objectToString(d) === '[object Date]';
}
exports.isDate = isDate;

function isError(e) {
  return (objectToString(e) === '[object Error]' || e instanceof Error);
}
exports.isError = isError;

function isFunction(arg) {
  return typeof arg === 'function';
}
exports.isFunction = isFunction;

function isPrimitive(arg) {
  return arg === null ||
         typeof arg === 'boolean' ||
         typeof arg === 'number' ||
         typeof arg === 'string' ||
         typeof arg === 'symbol' ||  // ES6 symbol
         typeof arg === 'undefined';
}
exports.isPrimitive = isPrimitive;

exports.isBuffer = Buffer.isBuffer;

function objectToString(o) {
  return Object.prototype.toString.call(o);
}

}).call(this,{"isBuffer":require("../../is-buffer/index.js")})
},{"../../is-buffer/index.js":11}],5:[function(require,module,exports){
(function (process){
/**
 * This is the web browser implementation of `debug()`.
 *
 * Expose `debug()` as the module.
 */

exports = module.exports = require('./debug');
exports.log = log;
exports.formatArgs = formatArgs;
exports.save = save;
exports.load = load;
exports.useColors = useColors;
exports.storage = 'undefined' != typeof chrome
               && 'undefined' != typeof chrome.storage
                  ? chrome.storage.local
                  : localstorage();

/**
 * Colors.
 */

exports.colors = [
  'lightseagreen',
  'forestgreen',
  'goldenrod',
  'dodgerblue',
  'darkorchid',
  'crimson'
];

/**
 * Currently only WebKit-based Web Inspectors, Firefox >= v31,
 * and the Firebug extension (any Firefox version) are known
 * to support "%c" CSS customizations.
 *
 * TODO: add a `localStorage` variable to explicitly enable/disable colors
 */

function useColors() {
  // NB: In an Electron preload script, document will be defined but not fully
  // initialized. Since we know we're in Chrome, we'll just detect this case
  // explicitly
  if (typeof window !== 'undefined' && window && typeof window.process !== 'undefined' && window.process.type === 'renderer') {
    return true;
  }

  // is webkit? http://stackoverflow.com/a/16459606/376773
  // document is undefined in react-native: https://github.com/facebook/react-native/pull/1632
  return (typeof document !== 'undefined' && document && 'WebkitAppearance' in document.documentElement.style) ||
    // is firebug? http://stackoverflow.com/a/398120/376773
    (typeof window !== 'undefined' && window && window.console && (console.firebug || (console.exception && console.table))) ||
    // is firefox >= v31?
    // https://developer.mozilla.org/en-US/docs/Tools/Web_Console#Styling_messages
    (typeof navigator !== 'undefined' && navigator && navigator.userAgent && navigator.userAgent.toLowerCase().match(/firefox\/(\d+)/) && parseInt(RegExp.$1, 10) >= 31) ||
    // double check webkit in userAgent just in case we are in a worker
    (typeof navigator !== 'undefined' && navigator && navigator.userAgent && navigator.userAgent.toLowerCase().match(/applewebkit\/(\d+)/));
}

/**
 * Map %j to `JSON.stringify()`, since no Web Inspectors do that by default.
 */

exports.formatters.j = function(v) {
  try {
    return JSON.stringify(v);
  } catch (err) {
    return '[UnexpectedJSONParseError]: ' + err.message;
  }
};


/**
 * Colorize log arguments if enabled.
 *
 * @api public
 */

function formatArgs(args) {
  var useColors = this.useColors;

  args[0] = (useColors ? '%c' : '')
    + this.namespace
    + (useColors ? ' %c' : ' ')
    + args[0]
    + (useColors ? '%c ' : ' ')
    + '+' + exports.humanize(this.diff);

  if (!useColors) return;

  var c = 'color: ' + this.color;
  args.splice(1, 0, c, 'color: inherit')

  // the final "%c" is somewhat tricky, because there could be other
  // arguments passed either before or after the %c, so we need to
  // figure out the correct index to insert the CSS into
  var index = 0;
  var lastC = 0;
  args[0].replace(/%[a-zA-Z%]/g, function(match) {
    if ('%%' === match) return;
    index++;
    if ('%c' === match) {
      // we only are interested in the *last* %c
      // (the user may have provided their own)
      lastC = index;
    }
  });

  args.splice(lastC, 0, c);
}

/**
 * Invokes `console.log()` when available.
 * No-op when `console.log` is not a "function".
 *
 * @api public
 */

function log() {
  // this hackery is required for IE8/9, where
  // the `console.log` function doesn't have 'apply'
  return 'object' === typeof console
    && console.log
    && Function.prototype.apply.call(console.log, console, arguments);
}

/**
 * Save `namespaces`.
 *
 * @param {String} namespaces
 * @api private
 */

function save(namespaces) {
  try {
    if (null == namespaces) {
      exports.storage.removeItem('debug');
    } else {
      exports.storage.debug = namespaces;
    }
  } catch(e) {}
}

/**
 * Load `namespaces`.
 *
 * @return {String} returns the previously persisted debug modes
 * @api private
 */

function load() {
  try {
    return exports.storage.debug;
  } catch(e) {}

  // If debug isn't set in LS, and we're in Electron, try to load $DEBUG
  if (typeof process !== 'undefined' && 'env' in process) {
    return process.env.DEBUG;
  }
}

/**
 * Enable namespaces listed in `localStorage.debug` initially.
 */

exports.enable(load());

/**
 * Localstorage attempts to return the localstorage.
 *
 * This is necessary because safari throws
 * when a user disables cookies/localstorage
 * and you attempt to access it.
 *
 * @return {LocalStorage}
 * @api private
 */

function localstorage() {
  try {
    return window.localStorage;
  } catch (e) {}
}

}).call(this,require('_process'))
},{"./debug":6,"_process":16}],6:[function(require,module,exports){

/**
 * This is the common logic for both the Node.js and web browser
 * implementations of `debug()`.
 *
 * Expose `debug()` as the module.
 */

exports = module.exports = createDebug.debug = createDebug.default = createDebug;
exports.coerce = coerce;
exports.disable = disable;
exports.enable = enable;
exports.enabled = enabled;
exports.humanize = require('ms');

/**
 * The currently active debug mode names, and names to skip.
 */

exports.names = [];
exports.skips = [];

/**
 * Map of special "%n" handling functions, for the debug "format" argument.
 *
 * Valid key names are a single, lower or upper-case letter, i.e. "n" and "N".
 */

exports.formatters = {};

/**
 * Previous log timestamp.
 */

var prevTime;

/**
 * Select a color.
 * @param {String} namespace
 * @return {Number}
 * @api private
 */

function selectColor(namespace) {
  var hash = 0, i;

  for (i in namespace) {
    hash  = ((hash << 5) - hash) + namespace.charCodeAt(i);
    hash |= 0; // Convert to 32bit integer
  }

  return exports.colors[Math.abs(hash) % exports.colors.length];
}

/**
 * Create a debugger with the given `namespace`.
 *
 * @param {String} namespace
 * @return {Function}
 * @api public
 */

function createDebug(namespace) {

  function debug() {
    // disabled?
    if (!debug.enabled) return;

    var self = debug;

    // set `diff` timestamp
    var curr = +new Date();
    var ms = curr - (prevTime || curr);
    self.diff = ms;
    self.prev = prevTime;
    self.curr = curr;
    prevTime = curr;

    // turn the `arguments` into a proper Array
    var args = new Array(arguments.length);
    for (var i = 0; i < args.length; i++) {
      args[i] = arguments[i];
    }

    args[0] = exports.coerce(args[0]);

    if ('string' !== typeof args[0]) {
      // anything else let's inspect with %O
      args.unshift('%O');
    }

    // apply any `formatters` transformations
    var index = 0;
    args[0] = args[0].replace(/%([a-zA-Z%])/g, function(match, format) {
      // if we encounter an escaped % then don't increase the array index
      if (match === '%%') return match;
      index++;
      var formatter = exports.formatters[format];
      if ('function' === typeof formatter) {
        var val = args[index];
        match = formatter.call(self, val);

        // now we need to remove `args[index]` since it's inlined in the `format`
        args.splice(index, 1);
        index--;
      }
      return match;
    });

    // apply env-specific formatting (colors, etc.)
    exports.formatArgs.call(self, args);

    var logFn = debug.log || exports.log || console.log.bind(console);
    logFn.apply(self, args);
  }

  debug.namespace = namespace;
  debug.enabled = exports.enabled(namespace);
  debug.useColors = exports.useColors();
  debug.color = selectColor(namespace);

  // env-specific initialization logic for debug instances
  if ('function' === typeof exports.init) {
    exports.init(debug);
  }

  return debug;
}

/**
 * Enables a debug mode by namespaces. This can include modes
 * separated by a colon and wildcards.
 *
 * @param {String} namespaces
 * @api public
 */

function enable(namespaces) {
  exports.save(namespaces);

  var split = (namespaces || '').split(/[\s,]+/);
  var len = split.length;

  for (var i = 0; i < len; i++) {
    if (!split[i]) continue; // ignore empty strings
    namespaces = split[i].replace(/\*/g, '.*?');
    if (namespaces[0] === '-') {
      exports.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
    } else {
      exports.names.push(new RegExp('^' + namespaces + '$'));
    }
  }
}

/**
 * Disable debug output.
 *
 * @api public
 */

function disable() {
  exports.enable('');
}

/**
 * Returns true if the given mode name is enabled, false otherwise.
 *
 * @param {String} name
 * @return {Boolean}
 * @api public
 */

function enabled(name) {
  var i, len;
  for (i = 0, len = exports.skips.length; i < len; i++) {
    if (exports.skips[i].test(name)) {
      return false;
    }
  }
  for (i = 0, len = exports.names.length; i < len; i++) {
    if (exports.names[i].test(name)) {
      return true;
    }
  }
  return false;
}

/**
 * Coerce `val`.
 *
 * @param {Mixed} val
 * @return {Mixed}
 * @api private
 */

function coerce(val) {
  if (val instanceof Error) return val.stack || val.message;
  return val;
}

},{"ms":14}],7:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

function EventEmitter() {
  this._events = this._events || {};
  this._maxListeners = this._maxListeners || undefined;
}
module.exports = EventEmitter;

// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;

EventEmitter.prototype._events = undefined;
EventEmitter.prototype._maxListeners = undefined;

// By default EventEmitters will print a warning if more than 10 listeners are
// added to it. This is a useful default which helps finding memory leaks.
EventEmitter.defaultMaxListeners = 10;

// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
EventEmitter.prototype.setMaxListeners = function(n) {
  if (!isNumber(n) || n < 0 || isNaN(n))
    throw TypeError('n must be a positive number');
  this._maxListeners = n;
  return this;
};

EventEmitter.prototype.emit = function(type) {
  var er, handler, len, args, i, listeners;

  if (!this._events)
    this._events = {};

  // If there is no 'error' event listener then throw.
  if (type === 'error') {
    if (!this._events.error ||
        (isObject(this._events.error) && !this._events.error.length)) {
      er = arguments[1];
      if (er instanceof Error) {
        throw er; // Unhandled 'error' event
      }
      throw TypeError('Uncaught, unspecified "error" event.');
    }
  }

  handler = this._events[type];

  if (isUndefined(handler))
    return false;

  if (isFunction(handler)) {
    switch (arguments.length) {
      // fast cases
      case 1:
        handler.call(this);
        break;
      case 2:
        handler.call(this, arguments[1]);
        break;
      case 3:
        handler.call(this, arguments[1], arguments[2]);
        break;
      // slower
      default:
        len = arguments.length;
        args = new Array(len - 1);
        for (i = 1; i < len; i++)
          args[i - 1] = arguments[i];
        handler.apply(this, args);
    }
  } else if (isObject(handler)) {
    len = arguments.length;
    args = new Array(len - 1);
    for (i = 1; i < len; i++)
      args[i - 1] = arguments[i];

    listeners = handler.slice();
    len = listeners.length;
    for (i = 0; i < len; i++)
      listeners[i].apply(this, args);
  }

  return true;
};

EventEmitter.prototype.addListener = function(type, listener) {
  var m;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events)
    this._events = {};

  // To avoid recursion in the case that type === "newListener"! Before
  // adding it to the listeners, first emit "newListener".
  if (this._events.newListener)
    this.emit('newListener', type,
              isFunction(listener.listener) ?
              listener.listener : listener);

  if (!this._events[type])
    // Optimize the case of one listener. Don't need the extra array object.
    this._events[type] = listener;
  else if (isObject(this._events[type]))
    // If we've already got an array, just append.
    this._events[type].push(listener);
  else
    // Adding the second element, need to change to array.
    this._events[type] = [this._events[type], listener];

  // Check for listener leak
  if (isObject(this._events[type]) && !this._events[type].warned) {
    var m;
    if (!isUndefined(this._maxListeners)) {
      m = this._maxListeners;
    } else {
      m = EventEmitter.defaultMaxListeners;
    }

    if (m && m > 0 && this._events[type].length > m) {
      this._events[type].warned = true;
      console.error('(node) warning: possible EventEmitter memory ' +
                    'leak detected. %d listeners added. ' +
                    'Use emitter.setMaxListeners() to increase limit.',
                    this._events[type].length);
      if (typeof console.trace === 'function') {
        // not supported in IE 10
        console.trace();
      }
    }
  }

  return this;
};

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

EventEmitter.prototype.once = function(type, listener) {
  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  var fired = false;

  function g() {
    this.removeListener(type, g);

    if (!fired) {
      fired = true;
      listener.apply(this, arguments);
    }
  }

  g.listener = listener;
  this.on(type, g);

  return this;
};

// emits a 'removeListener' event iff the listener was removed
EventEmitter.prototype.removeListener = function(type, listener) {
  var list, position, length, i;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events || !this._events[type])
    return this;

  list = this._events[type];
  length = list.length;
  position = -1;

  if (list === listener ||
      (isFunction(list.listener) && list.listener === listener)) {
    delete this._events[type];
    if (this._events.removeListener)
      this.emit('removeListener', type, listener);

  } else if (isObject(list)) {
    for (i = length; i-- > 0;) {
      if (list[i] === listener ||
          (list[i].listener && list[i].listener === listener)) {
        position = i;
        break;
      }
    }

    if (position < 0)
      return this;

    if (list.length === 1) {
      list.length = 0;
      delete this._events[type];
    } else {
      list.splice(position, 1);
    }

    if (this._events.removeListener)
      this.emit('removeListener', type, listener);
  }

  return this;
};

EventEmitter.prototype.removeAllListeners = function(type) {
  var key, listeners;

  if (!this._events)
    return this;

  // not listening for removeListener, no need to emit
  if (!this._events.removeListener) {
    if (arguments.length === 0)
      this._events = {};
    else if (this._events[type])
      delete this._events[type];
    return this;
  }

  // emit removeListener for all listeners on all events
  if (arguments.length === 0) {
    for (key in this._events) {
      if (key === 'removeListener') continue;
      this.removeAllListeners(key);
    }
    this.removeAllListeners('removeListener');
    this._events = {};
    return this;
  }

  listeners = this._events[type];

  if (isFunction(listeners)) {
    this.removeListener(type, listeners);
  } else {
    // LIFO order
    while (listeners.length)
      this.removeListener(type, listeners[listeners.length - 1]);
  }
  delete this._events[type];

  return this;
};

EventEmitter.prototype.listeners = function(type) {
  var ret;
  if (!this._events || !this._events[type])
    ret = [];
  else if (isFunction(this._events[type]))
    ret = [this._events[type]];
  else
    ret = this._events[type].slice();
  return ret;
};

EventEmitter.listenerCount = function(emitter, type) {
  var ret;
  if (!emitter._events || !emitter._events[type])
    ret = 0;
  else if (isFunction(emitter._events[type]))
    ret = 1;
  else
    ret = emitter._events[type].length;
  return ret;
};

function isFunction(arg) {
  return typeof arg === 'function';
}

function isNumber(arg) {
  return typeof arg === 'number';
}

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}

function isUndefined(arg) {
  return arg === void 0;
}

},{}],8:[function(require,module,exports){
var hat = module.exports = function (bits, base) {
    if (!base) base = 16;
    if (bits === undefined) bits = 128;
    if (bits <= 0) return '0';
    
    var digits = Math.log(Math.pow(2, bits)) / Math.log(base);
    for (var i = 2; digits === Infinity; i *= 2) {
        digits = Math.log(Math.pow(2, bits / i)) / Math.log(base) * i;
    }
    
    var rem = digits - Math.floor(digits);
    
    var res = '';
    
    for (var i = 0; i < Math.floor(digits); i++) {
        var x = Math.floor(Math.random() * base).toString(base);
        res = x + res;
    }
    
    if (rem) {
        var b = Math.pow(base, rem);
        var x = Math.floor(Math.random() * b).toString(base);
        res = x + res;
    }
    
    var parsed = parseInt(res, base);
    if (parsed !== Infinity && parsed >= Math.pow(2, bits)) {
        return hat(bits, base)
    }
    else return res;
};

hat.rack = function (bits, base, expandBy) {
    var fn = function (data) {
        var iters = 0;
        do {
            if (iters ++ > 10) {
                if (expandBy) bits += expandBy;
                else throw new Error('too many ID collisions, use more bits')
            }
            
            var id = hat(bits, base);
        } while (Object.hasOwnProperty.call(hats, id));
        
        hats[id] = data;
        return id;
    };
    var hats = fn.hats = {};
    
    fn.get = function (id) {
        return fn.hats[id];
    };
    
    fn.set = function (id, value) {
        fn.hats[id] = value;
        return fn;
    };
    
    fn.bits = bits || 128;
    fn.base = base || 16;
    return fn;
};

},{}],9:[function(require,module,exports){
exports.read = function (buffer, offset, isLE, mLen, nBytes) {
  var e, m
  var eLen = nBytes * 8 - mLen - 1
  var eMax = (1 << eLen) - 1
  var eBias = eMax >> 1
  var nBits = -7
  var i = isLE ? (nBytes - 1) : 0
  var d = isLE ? -1 : 1
  var s = buffer[offset + i]

  i += d

  e = s & ((1 << (-nBits)) - 1)
  s >>= (-nBits)
  nBits += eLen
  for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8) {}

  m = e & ((1 << (-nBits)) - 1)
  e >>= (-nBits)
  nBits += mLen
  for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8) {}

  if (e === 0) {
    e = 1 - eBias
  } else if (e === eMax) {
    return m ? NaN : ((s ? -1 : 1) * Infinity)
  } else {
    m = m + Math.pow(2, mLen)
    e = e - eBias
  }
  return (s ? -1 : 1) * m * Math.pow(2, e - mLen)
}

exports.write = function (buffer, value, offset, isLE, mLen, nBytes) {
  var e, m, c
  var eLen = nBytes * 8 - mLen - 1
  var eMax = (1 << eLen) - 1
  var eBias = eMax >> 1
  var rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0)
  var i = isLE ? 0 : (nBytes - 1)
  var d = isLE ? 1 : -1
  var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0

  value = Math.abs(value)

  if (isNaN(value) || value === Infinity) {
    m = isNaN(value) ? 1 : 0
    e = eMax
  } else {
    e = Math.floor(Math.log(value) / Math.LN2)
    if (value * (c = Math.pow(2, -e)) < 1) {
      e--
      c *= 2
    }
    if (e + eBias >= 1) {
      value += rt / c
    } else {
      value += rt * Math.pow(2, 1 - eBias)
    }
    if (value * c >= 2) {
      e++
      c /= 2
    }

    if (e + eBias >= eMax) {
      m = 0
      e = eMax
    } else if (e + eBias >= 1) {
      m = (value * c - 1) * Math.pow(2, mLen)
      e = e + eBias
    } else {
      m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen)
      e = 0
    }
  }

  for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {}

  e = (e << mLen) | m
  eLen += mLen
  for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {}

  buffer[offset + i - d] |= s * 128
}

},{}],10:[function(require,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    var TempCtor = function () {}
    TempCtor.prototype = superCtor.prototype
    ctor.prototype = new TempCtor()
    ctor.prototype.constructor = ctor
  }
}

},{}],11:[function(require,module,exports){
/*!
 * Determine if an object is a Buffer
 *
 * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * @license  MIT
 */

// The _isBuffer check is for Safari 5-7 support, because it's missing
// Object.prototype.constructor. Remove this eventually
module.exports = function (obj) {
  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
}

function isBuffer (obj) {
  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
}

// For Node v0.10 support. Remove this eventually.
function isSlowBuffer (obj) {
  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
}

},{}],12:[function(require,module,exports){
module.exports      = isTypedArray
isTypedArray.strict = isStrictTypedArray
isTypedArray.loose  = isLooseTypedArray

var toString = Object.prototype.toString
var names = {
    '[object Int8Array]': true
  , '[object Int16Array]': true
  , '[object Int32Array]': true
  , '[object Uint8Array]': true
  , '[object Uint16Array]': true
  , '[object Uint32Array]': true
  , '[object Float32Array]': true
  , '[object Float64Array]': true
}

function isTypedArray(arr) {
  return (
       isStrictTypedArray(arr)
    || isLooseTypedArray(arr)
  )
}

function isStrictTypedArray(arr) {
  return (
       arr instanceof Int8Array
    || arr instanceof Int16Array
    || arr instanceof Int32Array
    || arr instanceof Uint8Array
    || arr instanceof Uint16Array
    || arr instanceof Uint32Array
    || arr instanceof Float32Array
    || arr instanceof Float64Array
  )
}

function isLooseTypedArray(arr) {
  return names[toString.call(arr)]
}

},{}],13:[function(require,module,exports){
var toString = {}.toString;

module.exports = Array.isArray || function (arr) {
  return toString.call(arr) == '[object Array]';
};

},{}],14:[function(require,module,exports){
/**
 * Helpers.
 */

var s = 1000
var m = s * 60
var h = m * 60
var d = h * 24
var y = d * 365.25

/**
 * Parse or format the given `val`.
 *
 * Options:
 *
 *  - `long` verbose formatting [false]
 *
 * @param {String|Number} val
 * @param {Object} options
 * @throws {Error} throw an error if val is not a non-empty string or a number
 * @return {String|Number}
 * @api public
 */

module.exports = function (val, options) {
  options = options || {}
  var type = typeof val
  if (type === 'string' && val.length > 0) {
    return parse(val)
  } else if (type === 'number' && isNaN(val) === false) {
    return options.long ?
			fmtLong(val) :
			fmtShort(val)
  }
  throw new Error('val is not a non-empty string or a valid number. val=' + JSON.stringify(val))
}

/**
 * Parse the given `str` and return milliseconds.
 *
 * @param {String} str
 * @return {Number}
 * @api private
 */

function parse(str) {
  str = String(str)
  if (str.length > 10000) {
    return
  }
  var match = /^((?:\d+)?\.?\d+) *(milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|years?|yrs?|y)?$/i.exec(str)
  if (!match) {
    return
  }
  var n = parseFloat(match[1])
  var type = (match[2] || 'ms').toLowerCase()
  switch (type) {
    case 'years':
    case 'year':
    case 'yrs':
    case 'yr':
    case 'y':
      return n * y
    case 'days':
    case 'day':
    case 'd':
      return n * d
    case 'hours':
    case 'hour':
    case 'hrs':
    case 'hr':
    case 'h':
      return n * h
    case 'minutes':
    case 'minute':
    case 'mins':
    case 'min':
    case 'm':
      return n * m
    case 'seconds':
    case 'second':
    case 'secs':
    case 'sec':
    case 's':
      return n * s
    case 'milliseconds':
    case 'millisecond':
    case 'msecs':
    case 'msec':
    case 'ms':
      return n
    default:
      return undefined
  }
}

/**
 * Short format for `ms`.
 *
 * @param {Number} ms
 * @return {String}
 * @api private
 */

function fmtShort(ms) {
  if (ms >= d) {
    return Math.round(ms / d) + 'd'
  }
  if (ms >= h) {
    return Math.round(ms / h) + 'h'
  }
  if (ms >= m) {
    return Math.round(ms / m) + 'm'
  }
  if (ms >= s) {
    return Math.round(ms / s) + 's'
  }
  return ms + 'ms'
}

/**
 * Long format for `ms`.
 *
 * @param {Number} ms
 * @return {String}
 * @api private
 */

function fmtLong(ms) {
  return plural(ms, d, 'day') ||
    plural(ms, h, 'hour') ||
    plural(ms, m, 'minute') ||
    plural(ms, s, 'second') ||
    ms + ' ms'
}

/**
 * Pluralization helper.
 */

function plural(ms, n, name) {
  if (ms < n) {
    return
  }
  if (ms < n * 1.5) {
    return Math.floor(ms / n) + ' ' + name
  }
  return Math.ceil(ms / n) + ' ' + name + 's'
}

},{}],15:[function(require,module,exports){
var wrappy = require('wrappy')
module.exports = wrappy(once)
module.exports.strict = wrappy(onceStrict)

once.proto = once(function () {
  Object.defineProperty(Function.prototype, 'once', {
    value: function () {
      return once(this)
    },
    configurable: true
  })

  Object.defineProperty(Function.prototype, 'onceStrict', {
    value: function () {
      return onceStrict(this)
    },
    configurable: true
  })
})

function once (fn) {
  var f = function () {
    if (f.called) return f.value
    f.called = true
    return f.value = fn.apply(this, arguments)
  }
  f.called = false
  return f
}

function onceStrict (fn) {
  var f = function () {
    if (f.called)
      throw new Error(f.onceError)
    f.called = true
    return f.value = fn.apply(this, arguments)
  }
  var name = fn.name || 'Function wrapped with `once`'
  f.onceError = name + " shouldn't be called more than once"
  f.called = false
  return f
}

},{"wrappy":33}],16:[function(require,module,exports){
// shim for using process in browser

var process = module.exports = {};
var queue = [];
var draining = false;

function drainQueue() {
    if (draining) {
        return;
    }
    draining = true;
    var currentQueue;
    var len = queue.length;
    while(len) {
        currentQueue = queue;
        queue = [];
        var i = -1;
        while (++i < len) {
            currentQueue[i]();
        }
        len = queue.length;
    }
    draining = false;
}
process.nextTick = function (fun) {
    queue.push(fun);
    if (!draining) {
        setTimeout(drainQueue, 0);
    }
};

process.title = 'browser';
process.browser = true;
process.env = {};
process.argv = [];
process.version = ''; // empty string to avoid regexp issues
process.versions = {};

function noop() {}

process.on = noop;
process.addListener = noop;
process.once = noop;
process.off = noop;
process.removeListener = noop;
process.removeAllListeners = noop;
process.emit = noop;

process.binding = function (name) {
    throw new Error('process.binding is not supported');
};

// TODO(shtylman)
process.cwd = function () { return '/' };
process.chdir = function (dir) {
    throw new Error('process.chdir is not supported');
};
process.umask = function() { return 0; };

},{}],17:[function(require,module,exports){
(function (Buffer){
/* global Blob */

module.exports = Peer

var debug = require('debug')('simple-peer')
var extend = require('xtend/mutable')
var hat = require('hat')
var inherits = require('inherits')
var isTypedArray = require('is-typedarray')
var once = require('once')
var stream = require('stream')
var toBuffer = require('typedarray-to-buffer')

var wrtc
try {
  wrtc = require('wrtc') // webrtc in node - will be empty object in browser
} catch (err) {
  wrtc = {} // optional dependency failed to install
}

var RTCPeerConnection = typeof window !== 'undefined'
  ? window.mozRTCPeerConnection || window.RTCPeerConnection ||
    window.webkitRTCPeerConnection
  : wrtc.RTCPeerConnection

var RTCSessionDescription = typeof window !== 'undefined'
  ? window.mozRTCSessionDescription || window.RTCSessionDescription ||
    window.webkitRTCSessionDescription
  : wrtc.RTCSessionDescription

var RTCIceCandidate = typeof window !== 'undefined'
  ? window.mozRTCIceCandidate || window.RTCIceCandidate || window.webkitRTCIceCandidate
  : wrtc.RTCIceCandidate

inherits(Peer, stream.Duplex)

/**
 * WebRTC peer connection. Same API as node core `net.Socket`. Duplex stream.
 * @param {Object} opts
 */
function Peer (opts) {
  var self = this
  if (!(self instanceof Peer)) return new Peer(opts)
  if (!opts) opts = {}

  opts.allowHalfOpen = false
  stream.Duplex.call(self, opts)

  extend(self, {
    initiator: false,
    stream: false,
    config: Peer.config,
    constraints: Peer.constraints,
    channelName: (opts && opts.initiator) ? hat(160) : null,
    trickle: true
  }, opts)

  if (typeof RTCPeerConnection !== 'function') {
    if (typeof window === 'undefined') {
      throw new Error('Missing WebRTC support - was `wrtc` dependency installed?')
    } else {
      throw new Error('Missing WebRTC support - is this a supported browser?')
    }
  }

  self._debug('new peer (initiator: %s)', self.initiator)

  self.destroyed = false
  self.connected = false

  self._pcReady = false
  self._channelReady = false
  self._iceComplete = false // done with ice candidate trickle (got null candidate)
  self._channel = null
  self._buffer = []

  self._pc = new RTCPeerConnection(self.config, self.constraints)
  self._pc.oniceconnectionstatechange = self._onIceConnectionStateChange.bind(self)
  self._pc.onsignalingstatechange = self._onSignalingStateChange.bind(self)
  self._pc.onicecandidate = self._onIceCandidate.bind(self)

  if (self.stream) self._setupVideo(self.stream)
  self._pc.onaddstream = self._onAddStream.bind(self)

  if (self.initiator) {
    self._setupData({ channel: self._pc.createDataChannel(self.channelName) })
    self._pc.onnegotiationneeded = once(self._createOffer.bind(self))
    // Only Chrome triggers "negotiationneeded"; this is a workaround for other
    // implementations
    if (typeof window === 'undefined' || !window.webkitRTCPeerConnection) {
      self._pc.onnegotiationneeded()
    }
  } else {
    self._pc.ondatachannel = self._setupData.bind(self)
  }

  self.on('finish', function () {
    if (self.connected) {
      // When local peer is finished writing, close connection to remote peer.
      // Half open connections are currently not supported.
      // Wait a bit before destroying so the datachannel flushes.
      // TODO: does datachannels have a .end() that flushes and closes?
      setTimeout(function () {
        self._destroy()
      }, 100)
    } else {
      // If data channel is not connected when local peer is finished writing, wait until
      // data is flushed to network at "connect" event.
      // TODO: is there a more reliable way to accomplish this?
      self.once('connect', function () {
        setTimeout(function () {
          self._destroy()
        }, 100)
      })
    }
  })
}

/**
 * Expose config and constraints for overriding all Peer instances. Otherwise, just
 * set opts.config and opts.constraints when constructing a Peer.
 */
Peer.config = {
  iceServers: [
    {
      url: 'stun:23.21.150.121', // deprecated, replaced by `urls`
      urls: 'stun:23.21.150.121'
    }
  ]
}
Peer.constraints = {}

Peer.prototype.send = function (chunk, cb) {
  var self = this
  if (!cb) cb = noop
  self._write(chunk, undefined, cb)
}

Peer.prototype.signal = function (data) {
  var self = this
  if (self.destroyed) throw new Error('cannot signal after peer is destroyed')
  if (typeof data === 'string') {
    try {
      data = JSON.parse(data)
    } catch (err) {
      data = {}
    }
  }
  self._debug('signal')
  if (data.sdp) {
    self._pc.setRemoteDescription(new RTCSessionDescription(data), function () {
      if (self._pc.remoteDescription.type === 'offer') self._createAnswer()
    }, self._onError.bind(self))
  }
  if (data.candidate) {
    try {
      self._pc.addIceCandidate(
        new RTCIceCandidate(data.candidate), noop, self._onError.bind(self)
      )
    } catch (err) {
      self._destroy(new Error('error adding candidate: ' + err.message))
    }
  }
  if (!data.sdp && !data.candidate) {
    self._destroy(new Error('signal() called with invalid signal data'))
  }
}

Peer.prototype.destroy = function (onclose) {
  var self = this
  self._destroy(null, onclose)
}

Peer.prototype._destroy = function (err, onclose) {
  var self = this
  if (self.destroyed) return
  if (onclose) self.once('close', onclose)

  self._debug('destroy (error: %s)', err && err.message)

  self.destroyed = true
  self.connected = false
  self._pcReady = false
  self._channelReady = false

  if (self._pc) {
    try {
      self._pc.close()
    } catch (err) {}

    self._pc.oniceconnectionstatechange = null
    self._pc.onsignalingstatechange = null
    self._pc.onicecandidate = null
  }

  if (self._channel) {
    try {
      self._channel.close()
    } catch (err) {}

    self._channel.onmessage = null
    self._channel.onopen = null
    self._channel.onclose = null
  }
  self._pc = null
  self._channel = null

  this.readable = this.writable = false

  if (!self._readableState.ended) self.push(null)
  if (!self._writableState.finished) self.end()

  if (err) self.emit('error', err)
  self.emit('close')
}

Peer.prototype._setupData = function (event) {
  var self = this
  self._channel = event.channel
  self.channelName = self._channel.label

  self._channel.binaryType = 'arraybuffer'
  self._channel.onmessage = self._onChannelMessage.bind(self)
  self._channel.onopen = self._onChannelOpen.bind(self)
  self._channel.onclose = self._onChannelClose.bind(self)
}

Peer.prototype._setupVideo = function (stream) {
  var self = this
  self._pc.addStream(stream)
}

Peer.prototype._read = function () {}

/**
 * Send text/binary data to the remote peer.
 * @param {string|Buffer|TypedArrayView|ArrayBuffer|Blob} chunk
 * @param {string} encoding
 * @param {function} cb
 */
Peer.prototype._write = function (chunk, encoding, cb) {
  var self = this
  if (self.destroyed) return cb(new Error('cannot write after peer is destroyed'))

  var len = chunk.length || chunk.byteLength || chunk.size
  if (!self.connected) {
    self._debug('_write before ready: length %d', len)
    self._buffer.push(chunk)
    cb(null)
    return
  }
  self._debug('_write: length %d', len)

  if (isTypedArray.strict(chunk) || chunk instanceof ArrayBuffer ||
    typeof chunk === 'string' || (typeof Blob !== 'undefined' && chunk instanceof Blob)) {
    self._channel.send(chunk)
  } else if (Buffer.isBuffer(chunk)) {
    // node.js buffer
    self._channel.send(new Uint8Array(chunk))
  } else {
    self._channel.send(JSON.stringify(chunk))
  }

  cb(null)
}

Peer.prototype._createOffer = function () {
  var self = this
  if (self.destroyed) return

  self._pc.createOffer(function (offer) {
    if (self.destroyed) return
    speedHack(offer)
    self._pc.setLocalDescription(offer, noop, self._onError.bind(self))
    var sendOffer = function () {
      self.emit('signal', self._pc.localDescription || offer)
    }
    if (self.trickle || self._iceComplete) sendOffer()
    else self.once('_iceComplete', sendOffer) // wait for candidates
  }, self._onError.bind(self), self.offerConstraints)
}

Peer.prototype._createAnswer = function () {
  var self = this
  if (self.destroyed) return

  self._pc.createAnswer(function (answer) {
    if (self.destroyed) return
    speedHack(answer)
    self._pc.setLocalDescription(answer, noop, self._onError.bind(self))
    var sendAnswer = function () {
      self.emit('signal', self._pc.localDescription || answer)
    }
    if (self.trickle || self._iceComplete) sendAnswer()
    else self.once('_iceComplete', sendAnswer)
  }, self._onError.bind(self), self.answerConstraints)
}

Peer.prototype._onIceConnectionStateChange = function () {
  var self = this
  if (self.destroyed) return
  var iceGatheringState = self._pc.iceGatheringState
  var iceConnectionState = self._pc.iceConnectionState
  self.emit('iceConnectionStateChange', iceGatheringState, iceConnectionState)
  self._debug('iceConnectionStateChange %s %s', iceGatheringState, iceConnectionState)
  if (iceConnectionState === 'connected' || iceConnectionState === 'completed') {
    self._pcReady = true
    self._maybeReady()
  }
  if (iceConnectionState === 'disconnected' || iceConnectionState === 'closed') {
    self._destroy()
  }
}

Peer.prototype._maybeReady = function () {
  var self = this
  self._debug('maybeReady pc %s channel %s', self._pcReady, self._channelReady)
  if (!self.connected && self._pcReady && self._channelReady) {
    self.connected = true
    self._buffer.forEach(function (chunk) {
      self.send(chunk)
    })
    self._buffer = []

    self._debug('connect')
    self.emit('connect')
  }
}

Peer.prototype._onSignalingStateChange = function () {
  var self = this
  if (self.destroyed) return
  self.emit('signalingStateChange', self._pc.signalingState)
  self._debug('signalingStateChange %s', self._pc.signalingState)
}

Peer.prototype._onIceCandidate = function (event) {
  var self = this
  if (self.destroyed) return
  if (event.candidate && self.trickle) {
    self.emit('signal', { candidate: event.candidate })
  } else if (!event.candidate) {
    self._iceComplete = true
    self.emit('_iceComplete')
  }
}

Peer.prototype._onChannelMessage = function (event) {
  var self = this
  if (self.destroyed) return
  var data = event.data
  self._debug('on channel message: length %d', data.byteLength || data.length)

  if (data instanceof ArrayBuffer) {
    data = toBuffer(new Uint8Array(data))
    self.push(data)
  } else {
    try {
      data = JSON.parse(data)
    } catch (err) {}
    self.emit('data', data)
  }
}

Peer.prototype._onChannelOpen = function () {
  var self = this
  if (self.connected || self.destroyed) return
  self._debug('on channel open')
  self._channelReady = true
  self._maybeReady()
}

Peer.prototype._onChannelClose = function () {
  var self = this
  if (self.destroyed) return
  self._debug('on channel close')
  self._destroy()
}

Peer.prototype._onAddStream = function (event) {
  var self = this
  if (self.destroyed) return
  self._debug('on add stream')
  self.emit('stream', event.stream)
}

Peer.prototype._onError = function (err) {
  var self = this
  if (self.destroyed) return
  self._debug('error %s', err.message || err)
  self._destroy(err)
}

Peer.prototype._debug = function () {
  var self = this
  var args = [].slice.call(arguments)
  var id = self.channelName && self.channelName.substring(0, 7)
  args[0] = '[' + id + '] ' + args[0]
  debug.apply(null, args)
}

function speedHack (obj) {
  var s = obj.sdp.split('b=AS:30')
  if (s.length > 1) obj.sdp = s[0] + 'b=AS:1638400' + s[1]
}

function noop () {}

}).call(this,{"isBuffer":require("../is-buffer/index.js")})
},{"../is-buffer/index.js":11,"debug":5,"hat":8,"inherits":10,"is-typedarray":12,"once":15,"stream":18,"typedarray-to-buffer":31,"wrtc":2,"xtend/mutable":34}],18:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

module.exports = Stream;

var EE = require('events').EventEmitter;
var inherits = require('inherits');

inherits(Stream, EE);
Stream.Readable = require('readable-stream/readable.js');
Stream.Writable = require('readable-stream/writable.js');
Stream.Duplex = require('readable-stream/duplex.js');
Stream.Transform = require('readable-stream/transform.js');
Stream.PassThrough = require('readable-stream/passthrough.js');

// Backwards-compat with node 0.4.x
Stream.Stream = Stream;



// old-style streams.  Note that the pipe method (the only relevant
// part of this class) is overridden in the Readable class.

function Stream() {
  EE.call(this);
}

Stream.prototype.pipe = function(dest, options) {
  var source = this;

  function ondata(chunk) {
    if (dest.writable) {
      if (false === dest.write(chunk) && source.pause) {
        source.pause();
      }
    }
  }

  source.on('data', ondata);

  function ondrain() {
    if (source.readable && source.resume) {
      source.resume();
    }
  }

  dest.on('drain', ondrain);

  // If the 'end' option is not supplied, dest.end() will be called when
  // source gets the 'end' or 'close' events.  Only dest.end() once.
  if (!dest._isStdio && (!options || options.end !== false)) {
    source.on('end', onend);
    source.on('close', onclose);
  }

  var didOnEnd = false;
  function onend() {
    if (didOnEnd) return;
    didOnEnd = true;

    dest.end();
  }


  function onclose() {
    if (didOnEnd) return;
    didOnEnd = true;

    if (typeof dest.destroy === 'function') dest.destroy();
  }

  // don't leave dangling pipes when there are errors.
  function onerror(er) {
    cleanup();
    if (EE.listenerCount(this, 'error') === 0) {
      throw er; // Unhandled stream error in pipe.
    }
  }

  source.on('error', onerror);
  dest.on('error', onerror);

  // remove all the event listeners that were added.
  function cleanup() {
    source.removeListener('data', ondata);
    dest.removeListener('drain', ondrain);

    source.removeListener('end', onend);
    source.removeListener('close', onclose);

    source.removeListener('error', onerror);
    dest.removeListener('error', onerror);

    source.removeListener('end', cleanup);
    source.removeListener('close', cleanup);

    dest.removeListener('close', cleanup);
  }

  source.on('end', cleanup);
  source.on('close', cleanup);

  dest.on('close', cleanup);

  dest.emit('pipe', source);

  // Allow for unix-like usage: A.pipe(B).pipe(C)
  return dest;
};

},{"events":7,"inherits":10,"readable-stream/duplex.js":20,"readable-stream/passthrough.js":26,"readable-stream/readable.js":27,"readable-stream/transform.js":28,"readable-stream/writable.js":29}],19:[function(require,module,exports){
module.exports = Array.isArray || function (arr) {
  return Object.prototype.toString.call(arr) == '[object Array]';
};

},{}],20:[function(require,module,exports){
module.exports = require("./lib/_stream_duplex.js")

},{"./lib/_stream_duplex.js":21}],21:[function(require,module,exports){
(function (process){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// a duplex stream is just a stream that is both readable and writable.
// Since JS doesn't have multiple prototypal inheritance, this class
// prototypally inherits from Readable, and then parasitically from
// Writable.

module.exports = Duplex;

/*<replacement>*/
var objectKeys = Object.keys || function (obj) {
  var keys = [];
  for (var key in obj) keys.push(key);
  return keys;
}
/*</replacement>*/


/*<replacement>*/
var util = require('core-util-is');
util.inherits = require('inherits');
/*</replacement>*/

var Readable = require('./_stream_readable');
var Writable = require('./_stream_writable');

util.inherits(Duplex, Readable);

forEach(objectKeys(Writable.prototype), function(method) {
  if (!Duplex.prototype[method])
    Duplex.prototype[method] = Writable.prototype[method];
});

function Duplex(options) {
  if (!(this instanceof Duplex))
    return new Duplex(options);

  Readable.call(this, options);
  Writable.call(this, options);

  if (options && options.readable === false)
    this.readable = false;

  if (options && options.writable === false)
    this.writable = false;

  this.allowHalfOpen = true;
  if (options && options.allowHalfOpen === false)
    this.allowHalfOpen = false;

  this.once('end', onend);
}

// the no-half-open enforcer
function onend() {
  // if we allow half-open state, or if the writable side ended,
  // then we're ok.
  if (this.allowHalfOpen || this._writableState.ended)
    return;

  // no more data can be written.
  // But allow more writes to happen in this tick.
  process.nextTick(this.end.bind(this));
}

function forEach (xs, f) {
  for (var i = 0, l = xs.length; i < l; i++) {
    f(xs[i], i);
  }
}

}).call(this,require('_process'))
},{"./_stream_readable":23,"./_stream_writable":25,"_process":16,"core-util-is":4,"inherits":10}],22:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// a passthrough stream.
// basically just the most minimal sort of Transform stream.
// Every written chunk gets output as-is.

module.exports = PassThrough;

var Transform = require('./_stream_transform');

/*<replacement>*/
var util = require('core-util-is');
util.inherits = require('inherits');
/*</replacement>*/

util.inherits(PassThrough, Transform);

function PassThrough(options) {
  if (!(this instanceof PassThrough))
    return new PassThrough(options);

  Transform.call(this, options);
}

PassThrough.prototype._transform = function(chunk, encoding, cb) {
  cb(null, chunk);
};

},{"./_stream_transform":24,"core-util-is":4,"inherits":10}],23:[function(require,module,exports){
(function (process){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

module.exports = Readable;

/*<replacement>*/
var isArray = require('isarray');
/*</replacement>*/


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

Readable.ReadableState = ReadableState;

var EE = require('events').EventEmitter;

/*<replacement>*/
if (!EE.listenerCount) EE.listenerCount = function(emitter, type) {
  return emitter.listeners(type).length;
};
/*</replacement>*/

var Stream = require('stream');

/*<replacement>*/
var util = require('core-util-is');
util.inherits = require('inherits');
/*</replacement>*/

var StringDecoder;


/*<replacement>*/
var debug = require('util');
if (debug && debug.debuglog) {
  debug = debug.debuglog('stream');
} else {
  debug = function () {};
}
/*</replacement>*/


util.inherits(Readable, Stream);

function ReadableState(options, stream) {
  var Duplex = require('./_stream_duplex');

  options = options || {};

  // the point at which it stops calling _read() to fill the buffer
  // Note: 0 is a valid value, means "don't call _read preemptively ever"
  var hwm = options.highWaterMark;
  var defaultHwm = options.objectMode ? 16 : 16 * 1024;
  this.highWaterMark = (hwm || hwm === 0) ? hwm : defaultHwm;

  // cast to ints.
  this.highWaterMark = ~~this.highWaterMark;

  this.buffer = [];
  this.length = 0;
  this.pipes = null;
  this.pipesCount = 0;
  this.flowing = null;
  this.ended = false;
  this.endEmitted = false;
  this.reading = false;

  // a flag to be able to tell if the onwrite cb is called immediately,
  // or on a later tick.  We set this to true at first, because any
  // actions that shouldn't happen until "later" should generally also
  // not happen before the first write call.
  this.sync = true;

  // whenever we return null, then we set a flag to say
  // that we're awaiting a 'readable' event emission.
  this.needReadable = false;
  this.emittedReadable = false;
  this.readableListening = false;


  // object stream flag. Used to make read(n) ignore n and to
  // make all the buffer merging and length checks go away
  this.objectMode = !!options.objectMode;

  if (stream instanceof Duplex)
    this.objectMode = this.objectMode || !!options.readableObjectMode;

  // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.
  this.defaultEncoding = options.defaultEncoding || 'utf8';

  // when piping, we only care about 'readable' events that happen
  // after read()ing all the bytes and not getting any pushback.
  this.ranOut = false;

  // the number of writers that are awaiting a drain event in .pipe()s
  this.awaitDrain = 0;

  // if true, a maybeReadMore has been scheduled
  this.readingMore = false;

  this.decoder = null;
  this.encoding = null;
  if (options.encoding) {
    if (!StringDecoder)
      StringDecoder = require('string_decoder/').StringDecoder;
    this.decoder = new StringDecoder(options.encoding);
    this.encoding = options.encoding;
  }
}

function Readable(options) {
  var Duplex = require('./_stream_duplex');

  if (!(this instanceof Readable))
    return new Readable(options);

  this._readableState = new ReadableState(options, this);

  // legacy
  this.readable = true;

  Stream.call(this);
}

// Manually shove something into the read() buffer.
// This returns true if the highWaterMark has not been hit yet,
// similar to how Writable.write() returns true if you should
// write() some more.
Readable.prototype.push = function(chunk, encoding) {
  var state = this._readableState;

  if (util.isString(chunk) && !state.objectMode) {
    encoding = encoding || state.defaultEncoding;
    if (encoding !== state.encoding) {
      chunk = new Buffer(chunk, encoding);
      encoding = '';
    }
  }

  return readableAddChunk(this, state, chunk, encoding, false);
};

// Unshift should *always* be something directly out of read()
Readable.prototype.unshift = function(chunk) {
  var state = this._readableState;
  return readableAddChunk(this, state, chunk, '', true);
};

function readableAddChunk(stream, state, chunk, encoding, addToFront) {
  var er = chunkInvalid(state, chunk);
  if (er) {
    stream.emit('error', er);
  } else if (util.isNullOrUndefined(chunk)) {
    state.reading = false;
    if (!state.ended)
      onEofChunk(stream, state);
  } else if (state.objectMode || chunk && chunk.length > 0) {
    if (state.ended && !addToFront) {
      var e = new Error('stream.push() after EOF');
      stream.emit('error', e);
    } else if (state.endEmitted && addToFront) {
      var e = new Error('stream.unshift() after end event');
      stream.emit('error', e);
    } else {
      if (state.decoder && !addToFront && !encoding)
        chunk = state.decoder.write(chunk);

      if (!addToFront)
        state.reading = false;

      // if we want the data now, just emit it.
      if (state.flowing && state.length === 0 && !state.sync) {
        stream.emit('data', chunk);
        stream.read(0);
      } else {
        // update the buffer info.
        state.length += state.objectMode ? 1 : chunk.length;
        if (addToFront)
          state.buffer.unshift(chunk);
        else
          state.buffer.push(chunk);

        if (state.needReadable)
          emitReadable(stream);
      }

      maybeReadMore(stream, state);
    }
  } else if (!addToFront) {
    state.reading = false;
  }

  return needMoreData(state);
}



// if it's past the high water mark, we can push in some more.
// Also, if we have no data yet, we can stand some
// more bytes.  This is to work around cases where hwm=0,
// such as the repl.  Also, if the push() triggered a
// readable event, and the user called read(largeNumber) such that
// needReadable was set, then we ought to push more, so that another
// 'readable' event will be triggered.
function needMoreData(state) {
  return !state.ended &&
         (state.needReadable ||
          state.length < state.highWaterMark ||
          state.length === 0);
}

// backwards compatibility.
Readable.prototype.setEncoding = function(enc) {
  if (!StringDecoder)
    StringDecoder = require('string_decoder/').StringDecoder;
  this._readableState.decoder = new StringDecoder(enc);
  this._readableState.encoding = enc;
  return this;
};

// Don't raise the hwm > 128MB
var MAX_HWM = 0x800000;
function roundUpToNextPowerOf2(n) {
  if (n >= MAX_HWM) {
    n = MAX_HWM;
  } else {
    // Get the next highest power of 2
    n--;
    for (var p = 1; p < 32; p <<= 1) n |= n >> p;
    n++;
  }
  return n;
}

function howMuchToRead(n, state) {
  if (state.length === 0 && state.ended)
    return 0;

  if (state.objectMode)
    return n === 0 ? 0 : 1;

  if (isNaN(n) || util.isNull(n)) {
    // only flow one buffer at a time
    if (state.flowing && state.buffer.length)
      return state.buffer[0].length;
    else
      return state.length;
  }

  if (n <= 0)
    return 0;

  // If we're asking for more than the target buffer level,
  // then raise the water mark.  Bump up to the next highest
  // power of 2, to prevent increasing it excessively in tiny
  // amounts.
  if (n > state.highWaterMark)
    state.highWaterMark = roundUpToNextPowerOf2(n);

  // don't have that much.  return null, unless we've ended.
  if (n > state.length) {
    if (!state.ended) {
      state.needReadable = true;
      return 0;
    } else
      return state.length;
  }

  return n;
}

// you can override either this method, or the async _read(n) below.
Readable.prototype.read = function(n) {
  debug('read', n);
  var state = this._readableState;
  var nOrig = n;

  if (!util.isNumber(n) || n > 0)
    state.emittedReadable = false;

  // if we're doing read(0) to trigger a readable event, but we
  // already have a bunch of data in the buffer, then just trigger
  // the 'readable' event and move on.
  if (n === 0 &&
      state.needReadable &&
      (state.length >= state.highWaterMark || state.ended)) {
    debug('read: emitReadable', state.length, state.ended);
    if (state.length === 0 && state.ended)
      endReadable(this);
    else
      emitReadable(this);
    return null;
  }

  n = howMuchToRead(n, state);

  // if we've ended, and we're now clear, then finish it up.
  if (n === 0 && state.ended) {
    if (state.length === 0)
      endReadable(this);
    return null;
  }

  // All the actual chunk generation logic needs to be
  // *below* the call to _read.  The reason is that in certain
  // synthetic stream cases, such as passthrough streams, _read
  // may be a completely synchronous operation which may change
  // the state of the read buffer, providing enough data when
  // before there was *not* enough.
  //
  // So, the steps are:
  // 1. Figure out what the state of things will be after we do
  // a read from the buffer.
  //
  // 2. If that resulting state will trigger a _read, then call _read.
  // Note that this may be asynchronous, or synchronous.  Yes, it is
  // deeply ugly to write APIs this way, but that still doesn't mean
  // that the Readable class should behave improperly, as streams are
  // designed to be sync/async agnostic.
  // Take note if the _read call is sync or async (ie, if the read call
  // has returned yet), so that we know whether or not it's safe to emit
  // 'readable' etc.
  //
  // 3. Actually pull the requested chunks out of the buffer and return.

  // if we need a readable event, then we need to do some reading.
  var doRead = state.needReadable;
  debug('need readable', doRead);

  // if we currently have less than the highWaterMark, then also read some
  if (state.length === 0 || state.length - n < state.highWaterMark) {
    doRead = true;
    debug('length less than watermark', doRead);
  }

  // however, if we've ended, then there's no point, and if we're already
  // reading, then it's unnecessary.
  if (state.ended || state.reading) {
    doRead = false;
    debug('reading or ended', doRead);
  }

  if (doRead) {
    debug('do read');
    state.reading = true;
    state.sync = true;
    // if the length is currently zero, then we *need* a readable event.
    if (state.length === 0)
      state.needReadable = true;
    // call internal read method
    this._read(state.highWaterMark);
    state.sync = false;
  }

  // If _read pushed data synchronously, then `reading` will be false,
  // and we need to re-evaluate how much data we can return to the user.
  if (doRead && !state.reading)
    n = howMuchToRead(nOrig, state);

  var ret;
  if (n > 0)
    ret = fromList(n, state);
  else
    ret = null;

  if (util.isNull(ret)) {
    state.needReadable = true;
    n = 0;
  }

  state.length -= n;

  // If we have nothing in the buffer, then we want to know
  // as soon as we *do* get something into the buffer.
  if (state.length === 0 && !state.ended)
    state.needReadable = true;

  // If we tried to read() past the EOF, then emit end on the next tick.
  if (nOrig !== n && state.ended && state.length === 0)
    endReadable(this);

  if (!util.isNull(ret))
    this.emit('data', ret);

  return ret;
};

function chunkInvalid(state, chunk) {
  var er = null;
  if (!util.isBuffer(chunk) &&
      !util.isString(chunk) &&
      !util.isNullOrUndefined(chunk) &&
      !state.objectMode) {
    er = new TypeError('Invalid non-string/buffer chunk');
  }
  return er;
}


function onEofChunk(stream, state) {
  if (state.decoder && !state.ended) {
    var chunk = state.decoder.end();
    if (chunk && chunk.length) {
      state.buffer.push(chunk);
      state.length += state.objectMode ? 1 : chunk.length;
    }
  }
  state.ended = true;

  // emit 'readable' now to make sure it gets picked up.
  emitReadable(stream);
}

// Don't emit readable right away in sync mode, because this can trigger
// another read() call => stack overflow.  This way, it might trigger
// a nextTick recursion warning, but that's not so bad.
function emitReadable(stream) {
  var state = stream._readableState;
  state.needReadable = false;
  if (!state.emittedReadable) {
    debug('emitReadable', state.flowing);
    state.emittedReadable = true;
    if (state.sync)
      process.nextTick(function() {
        emitReadable_(stream);
      });
    else
      emitReadable_(stream);
  }
}

function emitReadable_(stream) {
  debug('emit readable');
  stream.emit('readable');
  flow(stream);
}


// at this point, the user has presumably seen the 'readable' event,
// and called read() to consume some data.  that may have triggered
// in turn another _read(n) call, in which case reading = true if
// it's in progress.
// However, if we're not ended, or reading, and the length < hwm,
// then go ahead and try to read some more preemptively.
function maybeReadMore(stream, state) {
  if (!state.readingMore) {
    state.readingMore = true;
    process.nextTick(function() {
      maybeReadMore_(stream, state);
    });
  }
}

function maybeReadMore_(stream, state) {
  var len = state.length;
  while (!state.reading && !state.flowing && !state.ended &&
         state.length < state.highWaterMark) {
    debug('maybeReadMore read 0');
    stream.read(0);
    if (len === state.length)
      // didn't get any data, stop spinning.
      break;
    else
      len = state.length;
  }
  state.readingMore = false;
}

// abstract method.  to be overridden in specific implementation classes.
// call cb(er, data) where data is <= n in length.
// for virtual (non-string, non-buffer) streams, "length" is somewhat
// arbitrary, and perhaps not very meaningful.
Readable.prototype._read = function(n) {
  this.emit('error', new Error('not implemented'));
};

Readable.prototype.pipe = function(dest, pipeOpts) {
  var src = this;
  var state = this._readableState;

  switch (state.pipesCount) {
    case 0:
      state.pipes = dest;
      break;
    case 1:
      state.pipes = [state.pipes, dest];
      break;
    default:
      state.pipes.push(dest);
      break;
  }
  state.pipesCount += 1;
  debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);

  var doEnd = (!pipeOpts || pipeOpts.end !== false) &&
              dest !== process.stdout &&
              dest !== process.stderr;

  var endFn = doEnd ? onend : cleanup;
  if (state.endEmitted)
    process.nextTick(endFn);
  else
    src.once('end', endFn);

  dest.on('unpipe', onunpipe);
  function onunpipe(readable) {
    debug('onunpipe');
    if (readable === src) {
      cleanup();
    }
  }

  function onend() {
    debug('onend');
    dest.end();
  }

  // when the dest drains, it reduces the awaitDrain counter
  // on the source.  This would be more elegant with a .once()
  // handler in flow(), but adding and removing repeatedly is
  // too slow.
  var ondrain = pipeOnDrain(src);
  dest.on('drain', ondrain);

  function cleanup() {
    debug('cleanup');
    // cleanup event handlers once the pipe is broken
    dest.removeListener('close', onclose);
    dest.removeListener('finish', onfinish);
    dest.removeListener('drain', ondrain);
    dest.removeListener('error', onerror);
    dest.removeListener('unpipe', onunpipe);
    src.removeListener('end', onend);
    src.removeListener('end', cleanup);
    src.removeListener('data', ondata);

    // if the reader is waiting for a drain event from this
    // specific writer, then it would cause it to never start
    // flowing again.
    // So, if this is awaiting a drain, then we just call it now.
    // If we don't know, then assume that we are waiting for one.
    if (state.awaitDrain &&
        (!dest._writableState || dest._writableState.needDrain))
      ondrain();
  }

  src.on('data', ondata);
  function ondata(chunk) {
    debug('ondata');
    var ret = dest.write(chunk);
    if (false === ret) {
      debug('false write response, pause',
            src._readableState.awaitDrain);
      src._readableState.awaitDrain++;
      src.pause();
    }
  }

  // if the dest has an error, then stop piping into it.
  // however, don't suppress the throwing behavior for this.
  function onerror(er) {
    debug('onerror', er);
    unpipe();
    dest.removeListener('error', onerror);
    if (EE.listenerCount(dest, 'error') === 0)
      dest.emit('error', er);
  }
  // This is a brutally ugly hack to make sure that our error handler
  // is attached before any userland ones.  NEVER DO THIS.
  if (!dest._events || !dest._events.error)
    dest.on('error', onerror);
  else if (isArray(dest._events.error))
    dest._events.error.unshift(onerror);
  else
    dest._events.error = [onerror, dest._events.error];



  // Both close and finish should trigger unpipe, but only once.
  function onclose() {
    dest.removeListener('finish', onfinish);
    unpipe();
  }
  dest.once('close', onclose);
  function onfinish() {
    debug('onfinish');
    dest.removeListener('close', onclose);
    unpipe();
  }
  dest.once('finish', onfinish);

  function unpipe() {
    debug('unpipe');
    src.unpipe(dest);
  }

  // tell the dest that it's being piped to
  dest.emit('pipe', src);

  // start the flow if it hasn't been started already.
  if (!state.flowing) {
    debug('pipe resume');
    src.resume();
  }

  return dest;
};

function pipeOnDrain(src) {
  return function() {
    var state = src._readableState;
    debug('pipeOnDrain', state.awaitDrain);
    if (state.awaitDrain)
      state.awaitDrain--;
    if (state.awaitDrain === 0 && EE.listenerCount(src, 'data')) {
      state.flowing = true;
      flow(src);
    }
  };
}


Readable.prototype.unpipe = function(dest) {
  var state = this._readableState;

  // if we're not piping anywhere, then do nothing.
  if (state.pipesCount === 0)
    return this;

  // just one destination.  most common case.
  if (state.pipesCount === 1) {
    // passed in one, but it's not the right one.
    if (dest && dest !== state.pipes)
      return this;

    if (!dest)
      dest = state.pipes;

    // got a match.
    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;
    if (dest)
      dest.emit('unpipe', this);
    return this;
  }

  // slow case. multiple pipe destinations.

  if (!dest) {
    // remove all.
    var dests = state.pipes;
    var len = state.pipesCount;
    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;

    for (var i = 0; i < len; i++)
      dests[i].emit('unpipe', this);
    return this;
  }

  // try to find the right one.
  var i = indexOf(state.pipes, dest);
  if (i === -1)
    return this;

  state.pipes.splice(i, 1);
  state.pipesCount -= 1;
  if (state.pipesCount === 1)
    state.pipes = state.pipes[0];

  dest.emit('unpipe', this);

  return this;
};

// set up data events if they are asked for
// Ensure readable listeners eventually get something
Readable.prototype.on = function(ev, fn) {
  var res = Stream.prototype.on.call(this, ev, fn);

  // If listening to data, and it has not explicitly been paused,
  // then call resume to start the flow of data on the next tick.
  if (ev === 'data' && false !== this._readableState.flowing) {
    this.resume();
  }

  if (ev === 'readable' && this.readable) {
    var state = this._readableState;
    if (!state.readableListening) {
      state.readableListening = true;
      state.emittedReadable = false;
      state.needReadable = true;
      if (!state.reading) {
        var self = this;
        process.nextTick(function() {
          debug('readable nexttick read 0');
          self.read(0);
        });
      } else if (state.length) {
        emitReadable(this, state);
      }
    }
  }

  return res;
};
Readable.prototype.addListener = Readable.prototype.on;

// pause() and resume() are remnants of the legacy readable stream API
// If the user uses them, then switch into old mode.
Readable.prototype.resume = function() {
  var state = this._readableState;
  if (!state.flowing) {
    debug('resume');
    state.flowing = true;
    if (!state.reading) {
      debug('resume read 0');
      this.read(0);
    }
    resume(this, state);
  }
  return this;
};

function resume(stream, state) {
  if (!state.resumeScheduled) {
    state.resumeScheduled = true;
    process.nextTick(function() {
      resume_(stream, state);
    });
  }
}

function resume_(stream, state) {
  state.resumeScheduled = false;
  stream.emit('resume');
  flow(stream);
  if (state.flowing && !state.reading)
    stream.read(0);
}

Readable.prototype.pause = function() {
  debug('call pause flowing=%j', this._readableState.flowing);
  if (false !== this._readableState.flowing) {
    debug('pause');
    this._readableState.flowing = false;
    this.emit('pause');
  }
  return this;
};

function flow(stream) {
  var state = stream._readableState;
  debug('flow', state.flowing);
  if (state.flowing) {
    do {
      var chunk = stream.read();
    } while (null !== chunk && state.flowing);
  }
}

// wrap an old-style stream as the async data source.
// This is *not* part of the readable stream interface.
// It is an ugly unfortunate mess of history.
Readable.prototype.wrap = function(stream) {
  var state = this._readableState;
  var paused = false;

  var self = this;
  stream.on('end', function() {
    debug('wrapped end');
    if (state.decoder && !state.ended) {
      var chunk = state.decoder.end();
      if (chunk && chunk.length)
        self.push(chunk);
    }

    self.push(null);
  });

  stream.on('data', function(chunk) {
    debug('wrapped data');
    if (state.decoder)
      chunk = state.decoder.write(chunk);
    if (!chunk || !state.objectMode && !chunk.length)
      return;

    var ret = self.push(chunk);
    if (!ret) {
      paused = true;
      stream.pause();
    }
  });

  // proxy all the other methods.
  // important when wrapping filters and duplexes.
  for (var i in stream) {
    if (util.isFunction(stream[i]) && util.isUndefined(this[i])) {
      this[i] = function(method) { return function() {
        return stream[method].apply(stream, arguments);
      }}(i);
    }
  }

  // proxy certain important events.
  var events = ['error', 'close', 'destroy', 'pause', 'resume'];
  forEach(events, function(ev) {
    stream.on(ev, self.emit.bind(self, ev));
  });

  // when we try to consume some more bytes, simply unpause the
  // underlying stream.
  self._read = function(n) {
    debug('wrapped _read', n);
    if (paused) {
      paused = false;
      stream.resume();
    }
  };

  return self;
};



// exposed for testing purposes only.
Readable._fromList = fromList;

// Pluck off n bytes from an array of buffers.
// Length is the combined lengths of all the buffers in the list.
function fromList(n, state) {
  var list = state.buffer;
  var length = state.length;
  var stringMode = !!state.decoder;
  var objectMode = !!state.objectMode;
  var ret;

  // nothing in the list, definitely empty.
  if (list.length === 0)
    return null;

  if (length === 0)
    ret = null;
  else if (objectMode)
    ret = list.shift();
  else if (!n || n >= length) {
    // read it all, truncate the array.
    if (stringMode)
      ret = list.join('');
    else
      ret = Buffer.concat(list, length);
    list.length = 0;
  } else {
    // read just some of it.
    if (n < list[0].length) {
      // just take a part of the first list item.
      // slice is the same for buffers and strings.
      var buf = list[0];
      ret = buf.slice(0, n);
      list[0] = buf.slice(n);
    } else if (n === list[0].length) {
      // first list is a perfect match
      ret = list.shift();
    } else {
      // complex case.
      // we have enough to cover it, but it spans past the first buffer.
      if (stringMode)
        ret = '';
      else
        ret = new Buffer(n);

      var c = 0;
      for (var i = 0, l = list.length; i < l && c < n; i++) {
        var buf = list[0];
        var cpy = Math.min(n - c, buf.length);

        if (stringMode)
          ret += buf.slice(0, cpy);
        else
          buf.copy(ret, c, 0, cpy);

        if (cpy < buf.length)
          list[0] = buf.slice(cpy);
        else
          list.shift();

        c += cpy;
      }
    }
  }

  return ret;
}

function endReadable(stream) {
  var state = stream._readableState;

  // If we get here before consuming all the bytes, then that is a
  // bug in node.  Should never happen.
  if (state.length > 0)
    throw new Error('endReadable called on non-empty stream');

  if (!state.endEmitted) {
    state.ended = true;
    process.nextTick(function() {
      // Check that we didn't get one last unshift.
      if (!state.endEmitted && state.length === 0) {
        state.endEmitted = true;
        stream.readable = false;
        stream.emit('end');
      }
    });
  }
}

function forEach (xs, f) {
  for (var i = 0, l = xs.length; i < l; i++) {
    f(xs[i], i);
  }
}

function indexOf (xs, x) {
  for (var i = 0, l = xs.length; i < l; i++) {
    if (xs[i] === x) return i;
  }
  return -1;
}

}).call(this,require('_process'))
},{"./_stream_duplex":21,"_process":16,"buffer":3,"core-util-is":4,"events":7,"inherits":10,"isarray":19,"stream":18,"string_decoder/":30,"util":2}],24:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.


// a transform stream is a readable/writable stream where you do
// something with the data.  Sometimes it's called a "filter",
// but that's not a great name for it, since that implies a thing where
// some bits pass through, and others are simply ignored.  (That would
// be a valid example of a transform, of course.)
//
// While the output is causally related to the input, it's not a
// necessarily symmetric or synchronous transformation.  For example,
// a zlib stream might take multiple plain-text writes(), and then
// emit a single compressed chunk some time in the future.
//
// Here's how this works:
//
// The Transform stream has all the aspects of the readable and writable
// stream classes.  When you write(chunk), that calls _write(chunk,cb)
// internally, and returns false if there's a lot of pending writes
// buffered up.  When you call read(), that calls _read(n) until
// there's enough pending readable data buffered up.
//
// In a transform stream, the written data is placed in a buffer.  When
// _read(n) is called, it transforms the queued up data, calling the
// buffered _write cb's as it consumes chunks.  If consuming a single
// written chunk would result in multiple output chunks, then the first
// outputted bit calls the readcb, and subsequent chunks just go into
// the read buffer, and will cause it to emit 'readable' if necessary.
//
// This way, back-pressure is actually determined by the reading side,
// since _read has to be called to start processing a new chunk.  However,
// a pathological inflate type of transform can cause excessive buffering
// here.  For example, imagine a stream where every byte of input is
// interpreted as an integer from 0-255, and then results in that many
// bytes of output.  Writing the 4 bytes {ff,ff,ff,ff} would result in
// 1kb of data being output.  In this case, you could write a very small
// amount of input, and end up with a very large amount of output.  In
// such a pathological inflating mechanism, there'd be no way to tell
// the system to stop doing the transform.  A single 4MB write could
// cause the system to run out of memory.
//
// However, even in such a pathological case, only a single written chunk
// would be consumed, and then the rest would wait (un-transformed) until
// the results of the previous transformed chunk were consumed.

module.exports = Transform;

var Duplex = require('./_stream_duplex');

/*<replacement>*/
var util = require('core-util-is');
util.inherits = require('inherits');
/*</replacement>*/

util.inherits(Transform, Duplex);


function TransformState(options, stream) {
  this.afterTransform = function(er, data) {
    return afterTransform(stream, er, data);
  };

  this.needTransform = false;
  this.transforming = false;
  this.writecb = null;
  this.writechunk = null;
}

function afterTransform(stream, er, data) {
  var ts = stream._transformState;
  ts.transforming = false;

  var cb = ts.writecb;

  if (!cb)
    return stream.emit('error', new Error('no writecb in Transform class'));

  ts.writechunk = null;
  ts.writecb = null;

  if (!util.isNullOrUndefined(data))
    stream.push(data);

  if (cb)
    cb(er);

  var rs = stream._readableState;
  rs.reading = false;
  if (rs.needReadable || rs.length < rs.highWaterMark) {
    stream._read(rs.highWaterMark);
  }
}


function Transform(options) {
  if (!(this instanceof Transform))
    return new Transform(options);

  Duplex.call(this, options);

  this._transformState = new TransformState(options, this);

  // when the writable side finishes, then flush out anything remaining.
  var stream = this;

  // start out asking for a readable event once data is transformed.
  this._readableState.needReadable = true;

  // we have implemented the _read method, and done the other things
  // that Readable wants before the first _read call, so unset the
  // sync guard flag.
  this._readableState.sync = false;

  this.once('prefinish', function() {
    if (util.isFunction(this._flush))
      this._flush(function(er) {
        done(stream, er);
      });
    else
      done(stream);
  });
}

Transform.prototype.push = function(chunk, encoding) {
  this._transformState.needTransform = false;
  return Duplex.prototype.push.call(this, chunk, encoding);
};

// This is the part where you do stuff!
// override this function in implementation classes.
// 'chunk' is an input chunk.
//
// Call `push(newChunk)` to pass along transformed output
// to the readable side.  You may call 'push' zero or more times.
//
// Call `cb(err)` when you are done with this chunk.  If you pass
// an error, then that'll put the hurt on the whole operation.  If you
// never call cb(), then you'll never get another chunk.
Transform.prototype._transform = function(chunk, encoding, cb) {
  throw new Error('not implemented');
};

Transform.prototype._write = function(chunk, encoding, cb) {
  var ts = this._transformState;
  ts.writecb = cb;
  ts.writechunk = chunk;
  ts.writeencoding = encoding;
  if (!ts.transforming) {
    var rs = this._readableState;
    if (ts.needTransform ||
        rs.needReadable ||
        rs.length < rs.highWaterMark)
      this._read(rs.highWaterMark);
  }
};

// Doesn't matter what the args are here.
// _transform does all the work.
// That we got here means that the readable side wants more data.
Transform.prototype._read = function(n) {
  var ts = this._transformState;

  if (!util.isNull(ts.writechunk) && ts.writecb && !ts.transforming) {
    ts.transforming = true;
    this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
  } else {
    // mark that we need a transform, so that any data that comes in
    // will get processed, now that we've asked for it.
    ts.needTransform = true;
  }
};


function done(stream, er) {
  if (er)
    return stream.emit('error', er);

  // if there's nothing in the write buffer, then that means
  // that nothing more will ever be provided
  var ws = stream._writableState;
  var ts = stream._transformState;

  if (ws.length)
    throw new Error('calling transform done when ws.length != 0');

  if (ts.transforming)
    throw new Error('calling transform done when still transforming');

  return stream.push(null);
}

},{"./_stream_duplex":21,"core-util-is":4,"inherits":10}],25:[function(require,module,exports){
(function (process){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// A bit simpler than readable streams.
// Implement an async ._write(chunk, cb), and it'll handle all
// the drain event emission and buffering.

module.exports = Writable;

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

Writable.WritableState = WritableState;


/*<replacement>*/
var util = require('core-util-is');
util.inherits = require('inherits');
/*</replacement>*/

var Stream = require('stream');

util.inherits(Writable, Stream);

function WriteReq(chunk, encoding, cb) {
  this.chunk = chunk;
  this.encoding = encoding;
  this.callback = cb;
}

function WritableState(options, stream) {
  var Duplex = require('./_stream_duplex');

  options = options || {};

  // the point at which write() starts returning false
  // Note: 0 is a valid value, means that we always return false if
  // the entire buffer is not flushed immediately on write()
  var hwm = options.highWaterMark;
  var defaultHwm = options.objectMode ? 16 : 16 * 1024;
  this.highWaterMark = (hwm || hwm === 0) ? hwm : defaultHwm;

  // object stream flag to indicate whether or not this stream
  // contains buffers or objects.
  this.objectMode = !!options.objectMode;

  if (stream instanceof Duplex)
    this.objectMode = this.objectMode || !!options.writableObjectMode;

  // cast to ints.
  this.highWaterMark = ~~this.highWaterMark;

  this.needDrain = false;
  // at the start of calling end()
  this.ending = false;
  // when end() has been called, and returned
  this.ended = false;
  // when 'finish' is emitted
  this.finished = false;

  // should we decode strings into buffers before passing to _write?
  // this is here so that some node-core streams can optimize string
  // handling at a lower level.
  var noDecode = options.decodeStrings === false;
  this.decodeStrings = !noDecode;

  // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.
  this.defaultEncoding = options.defaultEncoding || 'utf8';

  // not an actual buffer we keep track of, but a measurement
  // of how much we're waiting to get pushed to some underlying
  // socket or file.
  this.length = 0;

  // a flag to see when we're in the middle of a write.
  this.writing = false;

  // when true all writes will be buffered until .uncork() call
  this.corked = 0;

  // a flag to be able to tell if the onwrite cb is called immediately,
  // or on a later tick.  We set this to true at first, because any
  // actions that shouldn't happen until "later" should generally also
  // not happen before the first write call.
  this.sync = true;

  // a flag to know if we're processing previously buffered items, which
  // may call the _write() callback in the same tick, so that we don't
  // end up in an overlapped onwrite situation.
  this.bufferProcessing = false;

  // the callback that's passed to _write(chunk,cb)
  this.onwrite = function(er) {
    onwrite(stream, er);
  };

  // the callback that the user supplies to write(chunk,encoding,cb)
  this.writecb = null;

  // the amount that is being written when _write is called.
  this.writelen = 0;

  this.buffer = [];

  // number of pending user-supplied write callbacks
  // this must be 0 before 'finish' can be emitted
  this.pendingcb = 0;

  // emit prefinish if the only thing we're waiting for is _write cbs
  // This is relevant for synchronous Transform streams
  this.prefinished = false;

  // True if the error was already emitted and should not be thrown again
  this.errorEmitted = false;
}

function Writable(options) {
  var Duplex = require('./_stream_duplex');

  // Writable ctor is applied to Duplexes, though they're not
  // instanceof Writable, they're instanceof Readable.
  if (!(this instanceof Writable) && !(this instanceof Duplex))
    return new Writable(options);

  this._writableState = new WritableState(options, this);

  // legacy.
  this.writable = true;

  Stream.call(this);
}

// Otherwise people can pipe Writable streams, which is just wrong.
Writable.prototype.pipe = function() {
  this.emit('error', new Error('Cannot pipe. Not readable.'));
};


function writeAfterEnd(stream, state, cb) {
  var er = new Error('write after end');
  // TODO: defer error events consistently everywhere, not just the cb
  stream.emit('error', er);
  process.nextTick(function() {
    cb(er);
  });
}

// If we get something that is not a buffer, string, null, or undefined,
// and we're not in objectMode, then that's an error.
// Otherwise stream chunks are all considered to be of length=1, and the
// watermarks determine how many objects to keep in the buffer, rather than
// how many bytes or characters.
function validChunk(stream, state, chunk, cb) {
  var valid = true;
  if (!util.isBuffer(chunk) &&
      !util.isString(chunk) &&
      !util.isNullOrUndefined(chunk) &&
      !state.objectMode) {
    var er = new TypeError('Invalid non-string/buffer chunk');
    stream.emit('error', er);
    process.nextTick(function() {
      cb(er);
    });
    valid = false;
  }
  return valid;
}

Writable.prototype.write = function(chunk, encoding, cb) {
  var state = this._writableState;
  var ret = false;

  if (util.isFunction(encoding)) {
    cb = encoding;
    encoding = null;
  }

  if (util.isBuffer(chunk))
    encoding = 'buffer';
  else if (!encoding)
    encoding = state.defaultEncoding;

  if (!util.isFunction(cb))
    cb = function() {};

  if (state.ended)
    writeAfterEnd(this, state, cb);
  else if (validChunk(this, state, chunk, cb)) {
    state.pendingcb++;
    ret = writeOrBuffer(this, state, chunk, encoding, cb);
  }

  return ret;
};

Writable.prototype.cork = function() {
  var state = this._writableState;

  state.corked++;
};

Writable.prototype.uncork = function() {
  var state = this._writableState;

  if (state.corked) {
    state.corked--;

    if (!state.writing &&
        !state.corked &&
        !state.finished &&
        !state.bufferProcessing &&
        state.buffer.length)
      clearBuffer(this, state);
  }
};

function decodeChunk(state, chunk, encoding) {
  if (!state.objectMode &&
      state.decodeStrings !== false &&
      util.isString(chunk)) {
    chunk = new Buffer(chunk, encoding);
  }
  return chunk;
}

// if we're already writing something, then just put this
// in the queue, and wait our turn.  Otherwise, call _write
// If we return false, then we need a drain event, so set that flag.
function writeOrBuffer(stream, state, chunk, encoding, cb) {
  chunk = decodeChunk(state, chunk, encoding);
  if (util.isBuffer(chunk))
    encoding = 'buffer';
  var len = state.objectMode ? 1 : chunk.length;

  state.length += len;

  var ret = state.length < state.highWaterMark;
  // we must ensure that previous needDrain will not be reset to false.
  if (!ret)
    state.needDrain = true;

  if (state.writing || state.corked)
    state.buffer.push(new WriteReq(chunk, encoding, cb));
  else
    doWrite(stream, state, false, len, chunk, encoding, cb);

  return ret;
}

function doWrite(stream, state, writev, len, chunk, encoding, cb) {
  state.writelen = len;
  state.writecb = cb;
  state.writing = true;
  state.sync = true;
  if (writev)
    stream._writev(chunk, state.onwrite);
  else
    stream._write(chunk, encoding, state.onwrite);
  state.sync = false;
}

function onwriteError(stream, state, sync, er, cb) {
  if (sync)
    process.nextTick(function() {
      state.pendingcb--;
      cb(er);
    });
  else {
    state.pendingcb--;
    cb(er);
  }

  stream._writableState.errorEmitted = true;
  stream.emit('error', er);
}

function onwriteStateUpdate(state) {
  state.writing = false;
  state.writecb = null;
  state.length -= state.writelen;
  state.writelen = 0;
}

function onwrite(stream, er) {
  var state = stream._writableState;
  var sync = state.sync;
  var cb = state.writecb;

  onwriteStateUpdate(state);

  if (er)
    onwriteError(stream, state, sync, er, cb);
  else {
    // Check if we're actually ready to finish, but don't emit yet
    var finished = needFinish(stream, state);

    if (!finished &&
        !state.corked &&
        !state.bufferProcessing &&
        state.buffer.length) {
      clearBuffer(stream, state);
    }

    if (sync) {
      process.nextTick(function() {
        afterWrite(stream, state, finished, cb);
      });
    } else {
      afterWrite(stream, state, finished, cb);
    }
  }
}

function afterWrite(stream, state, finished, cb) {
  if (!finished)
    onwriteDrain(stream, state);
  state.pendingcb--;
  cb();
  finishMaybe(stream, state);
}

// Must force callback to be called on nextTick, so that we don't
// emit 'drain' before the write() consumer gets the 'false' return
// value, and has a chance to attach a 'drain' listener.
function onwriteDrain(stream, state) {
  if (state.length === 0 && state.needDrain) {
    state.needDrain = false;
    stream.emit('drain');
  }
}


// if there's something in the buffer waiting, then process it
function clearBuffer(stream, state) {
  state.bufferProcessing = true;

  if (stream._writev && state.buffer.length > 1) {
    // Fast case, write everything using _writev()
    var cbs = [];
    for (var c = 0; c < state.buffer.length; c++)
      cbs.push(state.buffer[c].callback);

    // count the one we are adding, as well.
    // TODO(isaacs) clean this up
    state.pendingcb++;
    doWrite(stream, state, true, state.length, state.buffer, '', function(err) {
      for (var i = 0; i < cbs.length; i++) {
        state.pendingcb--;
        cbs[i](err);
      }
    });

    // Clear buffer
    state.buffer = [];
  } else {
    // Slow case, write chunks one-by-one
    for (var c = 0; c < state.buffer.length; c++) {
      var entry = state.buffer[c];
      var chunk = entry.chunk;
      var encoding = entry.encoding;
      var cb = entry.callback;
      var len = state.objectMode ? 1 : chunk.length;

      doWrite(stream, state, false, len, chunk, encoding, cb);

      // if we didn't call the onwrite immediately, then
      // it means that we need to wait until it does.
      // also, that means that the chunk and cb are currently
      // being processed, so move the buffer counter past them.
      if (state.writing) {
        c++;
        break;
      }
    }

    if (c < state.buffer.length)
      state.buffer = state.buffer.slice(c);
    else
      state.buffer.length = 0;
  }

  state.bufferProcessing = false;
}

Writable.prototype._write = function(chunk, encoding, cb) {
  cb(new Error('not implemented'));

};

Writable.prototype._writev = null;

Writable.prototype.end = function(chunk, encoding, cb) {
  var state = this._writableState;

  if (util.isFunction(chunk)) {
    cb = chunk;
    chunk = null;
    encoding = null;
  } else if (util.isFunction(encoding)) {
    cb = encoding;
    encoding = null;
  }

  if (!util.isNullOrUndefined(chunk))
    this.write(chunk, encoding);

  // .end() fully uncorks
  if (state.corked) {
    state.corked = 1;
    this.uncork();
  }

  // ignore unnecessary end() calls.
  if (!state.ending && !state.finished)
    endWritable(this, state, cb);
};


function needFinish(stream, state) {
  return (state.ending &&
          state.length === 0 &&
          !state.finished &&
          !state.writing);
}

function prefinish(stream, state) {
  if (!state.prefinished) {
    state.prefinished = true;
    stream.emit('prefinish');
  }
}

function finishMaybe(stream, state) {
  var need = needFinish(stream, state);
  if (need) {
    if (state.pendingcb === 0) {
      prefinish(stream, state);
      state.finished = true;
      stream.emit('finish');
    } else
      prefinish(stream, state);
  }
  return need;
}

function endWritable(stream, state, cb) {
  state.ending = true;
  finishMaybe(stream, state);
  if (cb) {
    if (state.finished)
      process.nextTick(cb);
    else
      stream.once('finish', cb);
  }
  state.ended = true;
}

}).call(this,require('_process'))
},{"./_stream_duplex":21,"_process":16,"buffer":3,"core-util-is":4,"inherits":10,"stream":18}],26:[function(require,module,exports){
module.exports = require("./lib/_stream_passthrough.js")

},{"./lib/_stream_passthrough.js":22}],27:[function(require,module,exports){
(function (process){
exports = module.exports = require('./lib/_stream_readable.js');
exports.Stream = require('stream');
exports.Readable = exports;
exports.Writable = require('./lib/_stream_writable.js');
exports.Duplex = require('./lib/_stream_duplex.js');
exports.Transform = require('./lib/_stream_transform.js');
exports.PassThrough = require('./lib/_stream_passthrough.js');
if (!process.browser && process.env.READABLE_STREAM === 'disable') {
  module.exports = require('stream');
}

}).call(this,require('_process'))
},{"./lib/_stream_duplex.js":21,"./lib/_stream_passthrough.js":22,"./lib/_stream_readable.js":23,"./lib/_stream_transform.js":24,"./lib/_stream_writable.js":25,"_process":16,"stream":18}],28:[function(require,module,exports){
module.exports = require("./lib/_stream_transform.js")

},{"./lib/_stream_transform.js":24}],29:[function(require,module,exports){
module.exports = require("./lib/_stream_writable.js")

},{"./lib/_stream_writable.js":25}],30:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

var Buffer = require('buffer').Buffer;

var isBufferEncoding = Buffer.isEncoding
  || function(encoding) {
       switch (encoding && encoding.toLowerCase()) {
         case 'hex': case 'utf8': case 'utf-8': case 'ascii': case 'binary': case 'base64': case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': case 'raw': return true;
         default: return false;
       }
     }


function assertEncoding(encoding) {
  if (encoding && !isBufferEncoding(encoding)) {
    throw new Error('Unknown encoding: ' + encoding);
  }
}

// StringDecoder provides an interface for efficiently splitting a series of
// buffers into a series of JS strings without breaking apart multi-byte
// characters. CESU-8 is handled as part of the UTF-8 encoding.
//
// @TODO Handling all encodings inside a single object makes it very difficult
// to reason about this code, so it should be split up in the future.
// @TODO There should be a utf8-strict encoding that rejects invalid UTF-8 code
// points as used by CESU-8.
var StringDecoder = exports.StringDecoder = function(encoding) {
  this.encoding = (encoding || 'utf8').toLowerCase().replace(/[-_]/, '');
  assertEncoding(encoding);
  switch (this.encoding) {
    case 'utf8':
      // CESU-8 represents each of Surrogate Pair by 3-bytes
      this.surrogateSize = 3;
      break;
    case 'ucs2':
    case 'utf16le':
      // UTF-16 represents each of Surrogate Pair by 2-bytes
      this.surrogateSize = 2;
      this.detectIncompleteChar = utf16DetectIncompleteChar;
      break;
    case 'base64':
      // Base-64 stores 3 bytes in 4 chars, and pads the remainder.
      this.surrogateSize = 3;
      this.detectIncompleteChar = base64DetectIncompleteChar;
      break;
    default:
      this.write = passThroughWrite;
      return;
  }

  // Enough space to store all bytes of a single character. UTF-8 needs 4
  // bytes, but CESU-8 may require up to 6 (3 bytes per surrogate).
  this.charBuffer = new Buffer(6);
  // Number of bytes received for the current incomplete multi-byte character.
  this.charReceived = 0;
  // Number of bytes expected for the current incomplete multi-byte character.
  this.charLength = 0;
};


// write decodes the given buffer and returns it as JS string that is
// guaranteed to not contain any partial multi-byte characters. Any partial
// character found at the end of the buffer is buffered up, and will be
// returned when calling write again with the remaining bytes.
//
// Note: Converting a Buffer containing an orphan surrogate to a String
// currently works, but converting a String to a Buffer (via `new Buffer`, or
// Buffer#write) will replace incomplete surrogates with the unicode
// replacement character. See https://codereview.chromium.org/121173009/ .
StringDecoder.prototype.write = function(buffer) {
  var charStr = '';
  // if our last write ended with an incomplete multibyte character
  while (this.charLength) {
    // determine how many remaining bytes this buffer has to offer for this char
    var available = (buffer.length >= this.charLength - this.charReceived) ?
        this.charLength - this.charReceived :
        buffer.length;

    // add the new bytes to the char buffer
    buffer.copy(this.charBuffer, this.charReceived, 0, available);
    this.charReceived += available;

    if (this.charReceived < this.charLength) {
      // still not enough chars in this buffer? wait for more ...
      return '';
    }

    // remove bytes belonging to the current character from the buffer
    buffer = buffer.slice(available, buffer.length);

    // get the character that was split
    charStr = this.charBuffer.slice(0, this.charLength).toString(this.encoding);

    // CESU-8: lead surrogate (D800-DBFF) is also the incomplete character
    var charCode = charStr.charCodeAt(charStr.length - 1);
    if (charCode >= 0xD800 && charCode <= 0xDBFF) {
      this.charLength += this.surrogateSize;
      charStr = '';
      continue;
    }
    this.charReceived = this.charLength = 0;

    // if there are no more bytes in this buffer, just emit our char
    if (buffer.length === 0) {
      return charStr;
    }
    break;
  }

  // determine and set charLength / charReceived
  this.detectIncompleteChar(buffer);

  var end = buffer.length;
  if (this.charLength) {
    // buffer the incomplete character bytes we got
    buffer.copy(this.charBuffer, 0, buffer.length - this.charReceived, end);
    end -= this.charReceived;
  }

  charStr += buffer.toString(this.encoding, 0, end);

  var end = charStr.length - 1;
  var charCode = charStr.charCodeAt(end);
  // CESU-8: lead surrogate (D800-DBFF) is also the incomplete character
  if (charCode >= 0xD800 && charCode <= 0xDBFF) {
    var size = this.surrogateSize;
    this.charLength += size;
    this.charReceived += size;
    this.charBuffer.copy(this.charBuffer, size, 0, size);
    buffer.copy(this.charBuffer, 0, 0, size);
    return charStr.substring(0, end);
  }

  // or just emit the charStr
  return charStr;
};

// detectIncompleteChar determines if there is an incomplete UTF-8 character at
// the end of the given buffer. If so, it sets this.charLength to the byte
// length that character, and sets this.charReceived to the number of bytes
// that are available for this character.
StringDecoder.prototype.detectIncompleteChar = function(buffer) {
  // determine how many bytes we have to check at the end of this buffer
  var i = (buffer.length >= 3) ? 3 : buffer.length;

  // Figure out if one of the last i bytes of our buffer announces an
  // incomplete char.
  for (; i > 0; i--) {
    var c = buffer[buffer.length - i];

    // See http://en.wikipedia.org/wiki/UTF-8#Description

    // 110XXXXX
    if (i == 1 && c >> 5 == 0x06) {
      this.charLength = 2;
      break;
    }

    // 1110XXXX
    if (i <= 2 && c >> 4 == 0x0E) {
      this.charLength = 3;
      break;
    }

    // 11110XXX
    if (i <= 3 && c >> 3 == 0x1E) {
      this.charLength = 4;
      break;
    }
  }
  this.charReceived = i;
};

StringDecoder.prototype.end = function(buffer) {
  var res = '';
  if (buffer && buffer.length)
    res = this.write(buffer);

  if (this.charReceived) {
    var cr = this.charReceived;
    var buf = this.charBuffer;
    var enc = this.encoding;
    res += buf.slice(0, cr).toString(enc);
  }

  return res;
};

function passThroughWrite(buffer) {
  return buffer.toString(this.encoding);
}

function utf16DetectIncompleteChar(buffer) {
  this.charReceived = buffer.length % 2;
  this.charLength = this.charReceived ? 2 : 0;
}

function base64DetectIncompleteChar(buffer) {
  this.charReceived = buffer.length % 3;
  this.charLength = this.charReceived ? 3 : 0;
}

},{"buffer":3}],31:[function(require,module,exports){
(function (Buffer){
/**
 * Convert a typed array to a Buffer without a copy
 *
 * Author:   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * License:  MIT
 *
 * `npm install typedarray-to-buffer`
 */

var isTypedArray = require('is-typedarray').strict

module.exports = function typedarrayToBuffer (arr) {
  if (isTypedArray(arr)) {
    // To avoid a copy, use the typed array's underlying ArrayBuffer to back new Buffer
    var buf = new Buffer(arr.buffer)
    if (arr.byteLength !== arr.buffer.byteLength) {
      // Respect the "view", i.e. byteOffset and byteLength, without doing a copy
      buf = buf.slice(arr.byteOffset, arr.byteOffset + arr.byteLength)
    }
    return buf
  } else {
    // Pass through all other types to the `Buffer` constructor
    return new Buffer(arr)
  }
}

}).call(this,require("buffer").Buffer)
},{"buffer":3,"is-typedarray":32}],32:[function(require,module,exports){
module.exports      = isTypedArray
isTypedArray.strict = isStrictTypedArray
isTypedArray.loose  = isLooseTypedArray

var toString = Object.prototype.toString
var names = {
    '[object Int8Array]': true
  , '[object Int16Array]': true
  , '[object Int32Array]': true
  , '[object Uint8Array]': true
  , '[object Uint8ClampedArray]': true
  , '[object Uint16Array]': true
  , '[object Uint32Array]': true
  , '[object Float32Array]': true
  , '[object Float64Array]': true
}

function isTypedArray(arr) {
  return (
       isStrictTypedArray(arr)
    || isLooseTypedArray(arr)
  )
}

function isStrictTypedArray(arr) {
  return (
       arr instanceof Int8Array
    || arr instanceof Int16Array
    || arr instanceof Int32Array
    || arr instanceof Uint8Array
    || arr instanceof Uint8ClampedArray
    || arr instanceof Uint16Array
    || arr instanceof Uint32Array
    || arr instanceof Float32Array
    || arr instanceof Float64Array
  )
}

function isLooseTypedArray(arr) {
  return names[toString.call(arr)]
}

},{}],33:[function(require,module,exports){
// Returns a wrapper function that returns a wrapped callback
// The wrapper function should do some stuff, and return a
// presumably different callback function.
// This makes sure that own properties are retained, so that
// decorations and such are not lost along the way.
module.exports = wrappy
function wrappy (fn, cb) {
  if (fn && cb) return wrappy(fn)(cb)

  if (typeof fn !== 'function')
    throw new TypeError('need wrapper function')

  Object.keys(fn).forEach(function (k) {
    wrapper[k] = fn[k]
  })

  return wrapper

  function wrapper() {
    var args = new Array(arguments.length)
    for (var i = 0; i < args.length; i++) {
      args[i] = arguments[i]
    }
    var ret = fn.apply(this, args)
    var cb = args[args.length-1]
    if (typeof ret === 'function' && ret !== cb) {
      Object.keys(cb).forEach(function (k) {
        ret[k] = cb[k]
      })
    }
    return ret
  }
}

},{}],34:[function(require,module,exports){
module.exports = extend

var hasOwnProperty = Object.prototype.hasOwnProperty;

function extend(target) {
    for (var i = 1; i < arguments.length; i++) {
        var source = arguments[i]

        for (var key in source) {
            if (hasOwnProperty.call(source, key)) {
                target[key] = source[key]
            }
        }
    }

    return target
}

},{}]},{},[])("/browser")
});