jimp/browser/lib/jimp.js

An image processing library written entirely in JavaScript (i.e. zero external or native dependencies)

/*
Jimp v0.10.2
https://github.com/oliver-moran/jimp
Ported for the Web by Phil Seaton
MIT License

Copyright (c) 2018 Oliver Moran

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.
*/
if ((typeof(window)=='undefined' || !window) && (typeof(self)!='undefined')) var window = self;
(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.jimp = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
function _arrayWithHoles(arr) {
  if (Array.isArray(arr)) return arr;
}

module.exports = _arrayWithHoles;
},{}],2:[function(require,module,exports){
function _arrayWithoutHoles(arr) {
  if (Array.isArray(arr)) {
    for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) {
      arr2[i] = arr[i];
    }

    return arr2;
  }
}

module.exports = _arrayWithoutHoles;
},{}],3:[function(require,module,exports){
function _assertThisInitialized(self) {
  if (self === void 0) {
    throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
  }

  return self;
}

module.exports = _assertThisInitialized;
},{}],4:[function(require,module,exports){
function _classCallCheck(instance, Constructor) {
  if (!(instance instanceof Constructor)) {
    throw new TypeError("Cannot call a class as a function");
  }
}

module.exports = _classCallCheck;
},{}],5:[function(require,module,exports){
var setPrototypeOf = require("./setPrototypeOf");

function isNativeReflectConstruct() {
  if (typeof Reflect === "undefined" || !Reflect.construct) return false;
  if (Reflect.construct.sham) return false;
  if (typeof Proxy === "function") return true;

  try {
    Date.prototype.toString.call(Reflect.construct(Date, [], function () {}));
    return true;
  } catch (e) {
    return false;
  }
}

function _construct(Parent, args, Class) {
  if (isNativeReflectConstruct()) {
    module.exports = _construct = Reflect.construct;
  } else {
    module.exports = _construct = function _construct(Parent, args, Class) {
      var a = [null];
      a.push.apply(a, args);
      var Constructor = Function.bind.apply(Parent, a);
      var instance = new Constructor();
      if (Class) setPrototypeOf(instance, Class.prototype);
      return instance;
    };
  }

  return _construct.apply(null, arguments);
}

module.exports = _construct;
},{"./setPrototypeOf":17}],6:[function(require,module,exports){
function _defineProperties(target, props) {
  for (var i = 0; i < props.length; i++) {
    var descriptor = props[i];
    descriptor.enumerable = descriptor.enumerable || false;
    descriptor.configurable = true;
    if ("value" in descriptor) descriptor.writable = true;
    Object.defineProperty(target, descriptor.key, descriptor);
  }
}

function _createClass(Constructor, protoProps, staticProps) {
  if (protoProps) _defineProperties(Constructor.prototype, protoProps);
  if (staticProps) _defineProperties(Constructor, staticProps);
  return Constructor;
}

module.exports = _createClass;
},{}],7:[function(require,module,exports){
function _defineProperty(obj, key, value) {
  if (key in obj) {
    Object.defineProperty(obj, key, {
      value: value,
      enumerable: true,
      configurable: true,
      writable: true
    });
  } else {
    obj[key] = value;
  }

  return obj;
}

module.exports = _defineProperty;
},{}],8:[function(require,module,exports){
function _getPrototypeOf(o) {
  module.exports = _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) {
    return o.__proto__ || Object.getPrototypeOf(o);
  };
  return _getPrototypeOf(o);
}

module.exports = _getPrototypeOf;
},{}],9:[function(require,module,exports){
var setPrototypeOf = require("./setPrototypeOf");

function _inherits(subClass, superClass) {
  if (typeof superClass !== "function" && superClass !== null) {
    throw new TypeError("Super expression must either be null or a function");
  }

  subClass.prototype = Object.create(superClass && superClass.prototype, {
    constructor: {
      value: subClass,
      writable: true,
      configurable: true
    }
  });
  if (superClass) setPrototypeOf(subClass, superClass);
}

module.exports = _inherits;
},{"./setPrototypeOf":17}],10:[function(require,module,exports){
function _interopRequireDefault(obj) {
  return obj && obj.__esModule ? obj : {
    "default": obj
  };
}

module.exports = _interopRequireDefault;
},{}],11:[function(require,module,exports){
var _typeof = require("../helpers/typeof");

function _getRequireWildcardCache() {
  if (typeof WeakMap !== "function") return null;
  var cache = new WeakMap();

  _getRequireWildcardCache = function _getRequireWildcardCache() {
    return cache;
  };

  return cache;
}

function _interopRequireWildcard(obj) {
  if (obj && obj.__esModule) {
    return obj;
  }

  if (obj === null || _typeof(obj) !== "object" && typeof obj !== "function") {
    return {
      "default": obj
    };
  }

  var cache = _getRequireWildcardCache();

  if (cache && cache.has(obj)) {
    return cache.get(obj);
  }

  var newObj = {};
  var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor;

  for (var key in obj) {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null;

      if (desc && (desc.get || desc.set)) {
        Object.defineProperty(newObj, key, desc);
      } else {
        newObj[key] = obj[key];
      }
    }
  }

  newObj["default"] = obj;

  if (cache) {
    cache.set(obj, newObj);
  }

  return newObj;
}

module.exports = _interopRequireWildcard;
},{"../helpers/typeof":20}],12:[function(require,module,exports){
function _iterableToArray(iter) {
  if (Symbol.iterator in Object(iter) || Object.prototype.toString.call(iter) === "[object Arguments]") return Array.from(iter);
}

module.exports = _iterableToArray;
},{}],13:[function(require,module,exports){
function _iterableToArrayLimit(arr, i) {
  if (!(Symbol.iterator in Object(arr) || Object.prototype.toString.call(arr) === "[object Arguments]")) {
    return;
  }

  var _arr = [];
  var _n = true;
  var _d = false;
  var _e = undefined;

  try {
    for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) {
      _arr.push(_s.value);

      if (i && _arr.length === i) break;
    }
  } catch (err) {
    _d = true;
    _e = err;
  } finally {
    try {
      if (!_n && _i["return"] != null) _i["return"]();
    } finally {
      if (_d) throw _e;
    }
  }

  return _arr;
}

module.exports = _iterableToArrayLimit;
},{}],14:[function(require,module,exports){
function _nonIterableRest() {
  throw new TypeError("Invalid attempt to destructure non-iterable instance");
}

module.exports = _nonIterableRest;
},{}],15:[function(require,module,exports){
function _nonIterableSpread() {
  throw new TypeError("Invalid attempt to spread non-iterable instance");
}

module.exports = _nonIterableSpread;
},{}],16:[function(require,module,exports){
var _typeof = require("../helpers/typeof");

var assertThisInitialized = require("./assertThisInitialized");

function _possibleConstructorReturn(self, call) {
  if (call && (_typeof(call) === "object" || typeof call === "function")) {
    return call;
  }

  return assertThisInitialized(self);
}

module.exports = _possibleConstructorReturn;
},{"../helpers/typeof":20,"./assertThisInitialized":3}],17:[function(require,module,exports){
function _setPrototypeOf(o, p) {
  module.exports = _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
    o.__proto__ = p;
    return o;
  };

  return _setPrototypeOf(o, p);
}

module.exports = _setPrototypeOf;
},{}],18:[function(require,module,exports){
var arrayWithHoles = require("./arrayWithHoles");

var iterableToArrayLimit = require("./iterableToArrayLimit");

var nonIterableRest = require("./nonIterableRest");

function _slicedToArray(arr, i) {
  return arrayWithHoles(arr) || iterableToArrayLimit(arr, i) || nonIterableRest();
}

module.exports = _slicedToArray;
},{"./arrayWithHoles":1,"./iterableToArrayLimit":13,"./nonIterableRest":14}],19:[function(require,module,exports){
var arrayWithoutHoles = require("./arrayWithoutHoles");

var iterableToArray = require("./iterableToArray");

var nonIterableSpread = require("./nonIterableSpread");

function _toConsumableArray(arr) {
  return arrayWithoutHoles(arr) || iterableToArray(arr) || nonIterableSpread();
}

module.exports = _toConsumableArray;
},{"./arrayWithoutHoles":2,"./iterableToArray":12,"./nonIterableSpread":15}],20:[function(require,module,exports){
function _typeof2(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof2 = function _typeof2(obj) { return typeof obj; }; } else { _typeof2 = function _typeof2(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof2(obj); }

function _typeof(obj) {
  if (typeof Symbol === "function" && _typeof2(Symbol.iterator) === "symbol") {
    module.exports = _typeof = function _typeof(obj) {
      return _typeof2(obj);
    };
  } else {
    module.exports = _typeof = function _typeof(obj) {
      return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : _typeof2(obj);
    };
  }

  return _typeof(obj);
}

module.exports = _typeof;
},{}],21:[function(require,module,exports){
module.exports = require("regenerator-runtime");

},{"regenerator-runtime":332}],22:[function(require,module,exports){
var Converter = require('./src/converter');

/**
 * Function get source and destination alphabet and return convert function
 *
 * @param {string|Array} srcAlphabet
 * @param {string|Array} dstAlphabet
 *
 * @returns {function(number|Array)}
 */
function anyBase(srcAlphabet, dstAlphabet) {
    var converter = new Converter(srcAlphabet, dstAlphabet);
    /**
     * Convert function
     *
     * @param {string|Array} number
     *
     * @return {string|Array} number
     */
    return function (number) {
        return converter.convert(number);
    }
};

anyBase.BIN = '01';
anyBase.OCT = '01234567';
anyBase.DEC = '0123456789';
anyBase.HEX = '0123456789abcdef';

module.exports = anyBase;
},{"./src/converter":23}],23:[function(require,module,exports){
'use strict';

/**
 * Converter
 *
 * @param {string|Array} srcAlphabet
 * @param {string|Array} dstAlphabet
 * @constructor
 */
function Converter(srcAlphabet, dstAlphabet) {
    if (!srcAlphabet || !dstAlphabet || !srcAlphabet.length || !dstAlphabet.length) {
        throw new Error('Bad alphabet');
    }
    this.srcAlphabet = srcAlphabet;
    this.dstAlphabet = dstAlphabet;
}

/**
 * Convert number from source alphabet to destination alphabet
 *
 * @param {string|Array} number - number represented as a string or array of points
 *
 * @returns {string|Array}
 */
Converter.prototype.convert = function(number) {
    var i, divide, newlen,
    numberMap = {},
    fromBase = this.srcAlphabet.length,
    toBase = this.dstAlphabet.length,
    length = number.length,
    result = typeof number === 'string' ? '' : [];

    if (!this.isValid(number)) {
        throw new Error('Number "' + number + '" contains of non-alphabetic digits (' + this.srcAlphabet + ')');
    }

    if (this.srcAlphabet === this.dstAlphabet) {
        return number;
    }

    for (i = 0; i < length; i++) {
        numberMap[i] = this.srcAlphabet.indexOf(number[i]);
    }
    do {
        divide = 0;
        newlen = 0;
        for (i = 0; i < length; i++) {
            divide = divide * fromBase + numberMap[i];
            if (divide >= toBase) {
                numberMap[newlen++] = parseInt(divide / toBase, 10);
                divide = divide % toBase;
            } else if (newlen > 0) {
                numberMap[newlen++] = 0;
            }
        }
        length = newlen;
        result = this.dstAlphabet.slice(divide, divide + 1).concat(result);
    } while (newlen !== 0);

    return result;
};

/**
 * Valid number with source alphabet
 *
 * @param {number} number
 *
 * @returns {boolean}
 */
Converter.prototype.isValid = function(number) {
    var i = 0;
    for (; i < number.length; ++i) {
        if (this.srcAlphabet.indexOf(number[i]) === -1) {
            return false;
        }
    }
    return true;
};

module.exports = Converter;
},{}],24:[function(require,module,exports){
(function (global){
'use strict';

var objectAssign = require('object-assign');

// compare and isBuffer taken from https://github.com/feross/buffer/blob/680e9e5e488f22aac27599a57dc844a6315928dd/index.js
// original notice:

/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * @license  MIT
 */
function compare(a, b) {
  if (a === b) {
    return 0;
  }

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

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

  if (x < y) {
    return -1;
  }
  if (y < x) {
    return 1;
  }
  return 0;
}
function isBuffer(b) {
  if (global.Buffer && typeof global.Buffer.isBuffer === 'function') {
    return global.Buffer.isBuffer(b);
  }
  return !!(b != null && b._isBuffer);
}

// based on node assert, original notice:
// NB: The URL to the CommonJS spec is kept just for tradition.
//     node-assert has evolved a lot since then, both in API and behavior.

// http://wiki.commonjs.org/wiki/Unit_Testing/1.0
//
// THIS IS NOT TESTED NOR LIKELY TO WORK OUTSIDE V8!
//
// Originally from narwhal.js (http://narwhaljs.org)
// Copyright (c) 2009 Thomas Robinson <280north.com>
//
// 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 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 util = require('util/');
var hasOwn = Object.prototype.hasOwnProperty;
var pSlice = Array.prototype.slice;
var functionsHaveNames = (function () {
  return function foo() {}.name === 'foo';
}());
function pToString (obj) {
  return Object.prototype.toString.call(obj);
}
function isView(arrbuf) {
  if (isBuffer(arrbuf)) {
    return false;
  }
  if (typeof global.ArrayBuffer !== 'function') {
    return false;
  }
  if (typeof ArrayBuffer.isView === 'function') {
    return ArrayBuffer.isView(arrbuf);
  }
  if (!arrbuf) {
    return false;
  }
  if (arrbuf instanceof DataView) {
    return true;
  }
  if (arrbuf.buffer && arrbuf.buffer instanceof ArrayBuffer) {
    return true;
  }
  return false;
}
// 1. The assert module provides functions that throw
// AssertionError's when particular conditions are not met. The
// assert module must conform to the following interface.

var assert = module.exports = ok;

// 2. The AssertionError is defined in assert.
// new assert.AssertionError({ message: message,
//                             actual: actual,
//                             expected: expected })

var regex = /\s*function\s+([^\(\s]*)\s*/;
// based on https://github.com/ljharb/function.prototype.name/blob/adeeeec8bfcc6068b187d7d9fb3d5bb1d3a30899/implementation.js
function getName(func) {
  if (!util.isFunction(func)) {
    return;
  }
  if (functionsHaveNames) {
    return func.name;
  }
  var str = func.toString();
  var match = str.match(regex);
  return match && match[1];
}
assert.AssertionError = function AssertionError(options) {
  this.name = 'AssertionError';
  this.actual = options.actual;
  this.expected = options.expected;
  this.operator = options.operator;
  if (options.message) {
    this.message = options.message;
    this.generatedMessage = false;
  } else {
    this.message = getMessage(this);
    this.generatedMessage = true;
  }
  var stackStartFunction = options.stackStartFunction || fail;
  if (Error.captureStackTrace) {
    Error.captureStackTrace(this, stackStartFunction);
  } else {
    // non v8 browsers so we can have a stacktrace
    var err = new Error();
    if (err.stack) {
      var out = err.stack;

      // try to strip useless frames
      var fn_name = getName(stackStartFunction);
      var idx = out.indexOf('\n' + fn_name);
      if (idx >= 0) {
        // once we have located the function frame
        // we need to strip out everything before it (and its line)
        var next_line = out.indexOf('\n', idx + 1);
        out = out.substring(next_line + 1);
      }

      this.stack = out;
    }
  }
};

// assert.AssertionError instanceof Error
util.inherits(assert.AssertionError, Error);

function truncate(s, n) {
  if (typeof s === 'string') {
    return s.length < n ? s : s.slice(0, n);
  } else {
    return s;
  }
}
function inspect(something) {
  if (functionsHaveNames || !util.isFunction(something)) {
    return util.inspect(something);
  }
  var rawname = getName(something);
  var name = rawname ? ': ' + rawname : '';
  return '[Function' +  name + ']';
}
function getMessage(self) {
  return truncate(inspect(self.actual), 128) + ' ' +
         self.operator + ' ' +
         truncate(inspect(self.expected), 128);
}

// At present only the three keys mentioned above are used and
// understood by the spec. Implementations or sub modules can pass
// other keys to the AssertionError's constructor - they will be
// ignored.

// 3. All of the following functions must throw an AssertionError
// when a corresponding condition is not met, with a message that
// may be undefined if not provided.  All assertion methods provide
// both the actual and expected values to the assertion error for
// display purposes.

function fail(actual, expected, message, operator, stackStartFunction) {
  throw new assert.AssertionError({
    message: message,
    actual: actual,
    expected: expected,
    operator: operator,
    stackStartFunction: stackStartFunction
  });
}

// EXTENSION! allows for well behaved errors defined elsewhere.
assert.fail = fail;

// 4. Pure assertion tests whether a value is truthy, as determined
// by !!guard.
// assert.ok(guard, message_opt);
// This statement is equivalent to assert.equal(true, !!guard,
// message_opt);. To test strictly for the value true, use
// assert.strictEqual(true, guard, message_opt);.

function ok(value, message) {
  if (!value) fail(value, true, message, '==', assert.ok);
}
assert.ok = ok;

// 5. The equality assertion tests shallow, coercive equality with
// ==.
// assert.equal(actual, expected, message_opt);

assert.equal = function equal(actual, expected, message) {
  if (actual != expected) fail(actual, expected, message, '==', assert.equal);
};

// 6. The non-equality assertion tests for whether two objects are not equal
// with != assert.notEqual(actual, expected, message_opt);

assert.notEqual = function notEqual(actual, expected, message) {
  if (actual == expected) {
    fail(actual, expected, message, '!=', assert.notEqual);
  }
};

// 7. The equivalence assertion tests a deep equality relation.
// assert.deepEqual(actual, expected, message_opt);

assert.deepEqual = function deepEqual(actual, expected, message) {
  if (!_deepEqual(actual, expected, false)) {
    fail(actual, expected, message, 'deepEqual', assert.deepEqual);
  }
};

assert.deepStrictEqual = function deepStrictEqual(actual, expected, message) {
  if (!_deepEqual(actual, expected, true)) {
    fail(actual, expected, message, 'deepStrictEqual', assert.deepStrictEqual);
  }
};

function _deepEqual(actual, expected, strict, memos) {
  // 7.1. All identical values are equivalent, as determined by ===.
  if (actual === expected) {
    return true;
  } else if (isBuffer(actual) && isBuffer(expected)) {
    return compare(actual, expected) === 0;

  // 7.2. If the expected value is a Date object, the actual value is
  // equivalent if it is also a Date object that refers to the same time.
  } else if (util.isDate(actual) && util.isDate(expected)) {
    return actual.getTime() === expected.getTime();

  // 7.3 If the expected value is a RegExp object, the actual value is
  // equivalent if it is also a RegExp object with the same source and
  // properties (`global`, `multiline`, `lastIndex`, `ignoreCase`).
  } else if (util.isRegExp(actual) && util.isRegExp(expected)) {
    return actual.source === expected.source &&
           actual.global === expected.global &&
           actual.multiline === expected.multiline &&
           actual.lastIndex === expected.lastIndex &&
           actual.ignoreCase === expected.ignoreCase;

  // 7.4. Other pairs that do not both pass typeof value == 'object',
  // equivalence is determined by ==.
  } else if ((actual === null || typeof actual !== 'object') &&
             (expected === null || typeof expected !== 'object')) {
    return strict ? actual === expected : actual == expected;

  // If both values are instances of typed arrays, wrap their underlying
  // ArrayBuffers in a Buffer each to increase performance
  // This optimization requires the arrays to have the same type as checked by
  // Object.prototype.toString (aka pToString). Never perform binary
  // comparisons for Float*Arrays, though, since e.g. +0 === -0 but their
  // bit patterns are not identical.
  } else if (isView(actual) && isView(expected) &&
             pToString(actual) === pToString(expected) &&
             !(actual instanceof Float32Array ||
               actual instanceof Float64Array)) {
    return compare(new Uint8Array(actual.buffer),
                   new Uint8Array(expected.buffer)) === 0;

  // 7.5 For all other Object pairs, including Array objects, equivalence is
  // determined by having the same number of owned properties (as verified
  // with Object.prototype.hasOwnProperty.call), the same set of keys
  // (although not necessarily the same order), equivalent values for every
  // corresponding key, and an identical 'prototype' property. Note: this
  // accounts for both named and indexed properties on Arrays.
  } else if (isBuffer(actual) !== isBuffer(expected)) {
    return false;
  } else {
    memos = memos || {actual: [], expected: []};

    var actualIndex = memos.actual.indexOf(actual);
    if (actualIndex !== -1) {
      if (actualIndex === memos.expected.indexOf(expected)) {
        return true;
      }
    }

    memos.actual.push(actual);
    memos.expected.push(expected);

    return objEquiv(actual, expected, strict, memos);
  }
}

function isArguments(object) {
  return Object.prototype.toString.call(object) == '[object Arguments]';
}

function objEquiv(a, b, strict, actualVisitedObjects) {
  if (a === null || a === undefined || b === null || b === undefined)
    return false;
  // if one is a primitive, the other must be same
  if (util.isPrimitive(a) || util.isPrimitive(b))
    return a === b;
  if (strict && Object.getPrototypeOf(a) !== Object.getPrototypeOf(b))
    return false;
  var aIsArgs = isArguments(a);
  var bIsArgs = isArguments(b);
  if ((aIsArgs && !bIsArgs) || (!aIsArgs && bIsArgs))
    return false;
  if (aIsArgs) {
    a = pSlice.call(a);
    b = pSlice.call(b);
    return _deepEqual(a, b, strict);
  }
  var ka = objectKeys(a);
  var kb = objectKeys(b);
  var key, i;
  // having the same number of owned properties (keys incorporates
  // hasOwnProperty)
  if (ka.length !== kb.length)
    return false;
  //the same set of keys (although not necessarily the same order),
  ka.sort();
  kb.sort();
  //~~~cheap key test
  for (i = ka.length - 1; i >= 0; i--) {
    if (ka[i] !== kb[i])
      return false;
  }
  //equivalent values for every corresponding key, and
  //~~~possibly expensive deep test
  for (i = ka.length - 1; i >= 0; i--) {
    key = ka[i];
    if (!_deepEqual(a[key], b[key], strict, actualVisitedObjects))
      return false;
  }
  return true;
}

// 8. The non-equivalence assertion tests for any deep inequality.
// assert.notDeepEqual(actual, expected, message_opt);

assert.notDeepEqual = function notDeepEqual(actual, expected, message) {
  if (_deepEqual(actual, expected, false)) {
    fail(actual, expected, message, 'notDeepEqual', assert.notDeepEqual);
  }
};

assert.notDeepStrictEqual = notDeepStrictEqual;
function notDeepStrictEqual(actual, expected, message) {
  if (_deepEqual(actual, expected, true)) {
    fail(actual, expected, message, 'notDeepStrictEqual', notDeepStrictEqual);
  }
}


// 9. The strict equality assertion tests strict equality, as determined by ===.
// assert.strictEqual(actual, expected, message_opt);

assert.strictEqual = function strictEqual(actual, expected, message) {
  if (actual !== expected) {
    fail(actual, expected, message, '===', assert.strictEqual);
  }
};

// 10. The strict non-equality assertion tests for strict inequality, as
// determined by !==.  assert.notStrictEqual(actual, expected, message_opt);

assert.notStrictEqual = function notStrictEqual(actual, expected, message) {
  if (actual === expected) {
    fail(actual, expected, message, '!==', assert.notStrictEqual);
  }
};

function expectedException(actual, expected) {
  if (!actual || !expected) {
    return false;
  }

  if (Object.prototype.toString.call(expected) == '[object RegExp]') {
    return expected.test(actual);
  }

  try {
    if (actual instanceof expected) {
      return true;
    }
  } catch (e) {
    // Ignore.  The instanceof check doesn't work for arrow functions.
  }

  if (Error.isPrototypeOf(expected)) {
    return false;
  }

  return expected.call({}, actual) === true;
}

function _tryBlock(block) {
  var error;
  try {
    block();
  } catch (e) {
    error = e;
  }
  return error;
}

function _throws(shouldThrow, block, expected, message) {
  var actual;

  if (typeof block !== 'function') {
    throw new TypeError('"block" argument must be a function');
  }

  if (typeof expected === 'string') {
    message = expected;
    expected = null;
  }

  actual = _tryBlock(block);

  message = (expected && expected.name ? ' (' + expected.name + ').' : '.') +
            (message ? ' ' + message : '.');

  if (shouldThrow && !actual) {
    fail(actual, expected, 'Missing expected exception' + message);
  }

  var userProvidedMessage = typeof message === 'string';
  var isUnwantedException = !shouldThrow && util.isError(actual);
  var isUnexpectedException = !shouldThrow && actual && !expected;

  if ((isUnwantedException &&
      userProvidedMessage &&
      expectedException(actual, expected)) ||
      isUnexpectedException) {
    fail(actual, expected, 'Got unwanted exception' + message);
  }

  if ((shouldThrow && actual && expected &&
      !expectedException(actual, expected)) || (!shouldThrow && actual)) {
    throw actual;
  }
}

// 11. Expected to throw an error:
// assert.throws(block, Error_opt, message_opt);

assert.throws = function(block, /*optional*/error, /*optional*/message) {
  _throws(true, block, error, message);
};

// EXTENSION! This is annoying to write outside this module.
assert.doesNotThrow = function(block, /*optional*/error, /*optional*/message) {
  _throws(false, block, error, message);
};

assert.ifError = function(err) { if (err) throw err; };

// Expose a strict only variant of assert
function strict(value, message) {
  if (!value) fail(value, true, message, '==', strict);
}
assert.strict = objectAssign(strict, assert, {
  equal: assert.strictEqual,
  deepEqual: assert.deepStrictEqual,
  notEqual: assert.notStrictEqual,
  notDeepEqual: assert.notDeepStrictEqual
});
assert.strict.strict = assert.strict;

var objectKeys = Object.keys || function (obj) {
  var keys = [];
  for (var key in obj) {
    if (hasOwn.call(obj, key)) keys.push(key);
  }
  return keys;
};

}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"object-assign":263,"util/":27}],25:[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
  }
}

},{}],26:[function(require,module,exports){
module.exports = function isBuffer(arg) {
  return arg && typeof arg === 'object'
    && typeof arg.copy === 'function'
    && typeof arg.fill === 'function'
    && typeof arg.readUInt8 === 'function';
}
},{}],27:[function(require,module,exports){
(function (process,global){
// 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 formatRegExp = /%[sdj%]/g;
exports.format = function(f) {
  if (!isString(f)) {
    var objects = [];
    for (var i = 0; i < arguments.length; i++) {
      objects.push(inspect(arguments[i]));
    }
    return objects.join(' ');
  }

  var i = 1;
  var args = arguments;
  var len = args.length;
  var str = String(f).replace(formatRegExp, function(x) {
    if (x === '%%') return '%';
    if (i >= len) return x;
    switch (x) {
      case '%s': return String(args[i++]);
      case '%d': return Number(args[i++]);
      case '%j':
        try {
          return JSON.stringify(args[i++]);
        } catch (_) {
          return '[Circular]';
        }
      default:
        return x;
    }
  });
  for (var x = args[i]; i < len; x = args[++i]) {
    if (isNull(x) || !isObject(x)) {
      str += ' ' + x;
    } else {
      str += ' ' + inspect(x);
    }
  }
  return str;
};


// Mark that a method should not be used.
// Returns a modified function which warns once by default.
// If --no-deprecation is set, then it is a no-op.
exports.deprecate = function(fn, msg) {
  // Allow for deprecating things in the process of starting up.
  if (isUndefined(global.process)) {
    return function() {
      return exports.deprecate(fn, msg).apply(this, arguments);
    };
  }

  if (process.noDeprecation === true) {
    return fn;
  }

  var warned = false;
  function deprecated() {
    if (!warned) {
      if (process.throwDeprecation) {
        throw new Error(msg);
      } else if (process.traceDeprecation) {
        console.trace(msg);
      } else {
        console.error(msg);
      }
      warned = true;
    }
    return fn.apply(this, arguments);
  }

  return deprecated;
};


var debugs = {};
var debugEnviron;
exports.debuglog = function(set) {
  if (isUndefined(debugEnviron))
    debugEnviron = process.env.NODE_DEBUG || '';
  set = set.toUpperCase();
  if (!debugs[set]) {
    if (new RegExp('\\b' + set + '\\b', 'i').test(debugEnviron)) {
      var pid = process.pid;
      debugs[set] = function() {
        var msg = exports.format.apply(exports, arguments);
        console.error('%s %d: %s', set, pid, msg);
      };
    } else {
      debugs[set] = function() {};
    }
  }
  return debugs[set];
};


/**
 * Echos the value of a value. Trys to print the value out
 * in the best way possible given the different types.
 *
 * @param {Object} obj The object to print out.
 * @param {Object} opts Optional options object that alters the output.
 */
/* legacy: obj, showHidden, depth, colors*/
function inspect(obj, opts) {
  // default options
  var ctx = {
    seen: [],
    stylize: stylizeNoColor
  };
  // legacy...
  if (arguments.length >= 3) ctx.depth = arguments[2];
  if (arguments.length >= 4) ctx.colors = arguments[3];
  if (isBoolean(opts)) {
    // legacy...
    ctx.showHidden = opts;
  } else if (opts) {
    // got an "options" object
    exports._extend(ctx, opts);
  }
  // set default options
  if (isUndefined(ctx.showHidden)) ctx.showHidden = false;
  if (isUndefined(ctx.depth)) ctx.depth = 2;
  if (isUndefined(ctx.colors)) ctx.colors = false;
  if (isUndefined(ctx.customInspect)) ctx.customInspect = true;
  if (ctx.colors) ctx.stylize = stylizeWithColor;
  return formatValue(ctx, obj, ctx.depth);
}
exports.inspect = inspect;


// http://en.wikipedia.org/wiki/ANSI_escape_code#graphics
inspect.colors = {
  'bold' : [1, 22],
  'italic' : [3, 23],
  'underline' : [4, 24],
  'inverse' : [7, 27],
  'white' : [37, 39],
  'grey' : [90, 39],
  'black' : [30, 39],
  'blue' : [34, 39],
  'cyan' : [36, 39],
  'green' : [32, 39],
  'magenta' : [35, 39],
  'red' : [31, 39],
  'yellow' : [33, 39]
};

// Don't use 'blue' not visible on cmd.exe
inspect.styles = {
  'special': 'cyan',
  'number': 'yellow',
  'boolean': 'yellow',
  'undefined': 'grey',
  'null': 'bold',
  'string': 'green',
  'date': 'magenta',
  // "name": intentionally not styling
  'regexp': 'red'
};


function stylizeWithColor(str, styleType) {
  var style = inspect.styles[styleType];

  if (style) {
    return '\u001b[' + inspect.colors[style][0] + 'm' + str +
           '\u001b[' + inspect.colors[style][1] + 'm';
  } else {
    return str;
  }
}


function stylizeNoColor(str, styleType) {
  return str;
}


function arrayToHash(array) {
  var hash = {};

  array.forEach(function(val, idx) {
    hash[val] = true;
  });

  return hash;
}


function formatValue(ctx, value, recurseTimes) {
  // Provide a hook for user-specified inspect functions.
  // Check that value is an object with an inspect function on it
  if (ctx.customInspect &&
      value &&
      isFunction(value.inspect) &&
      // Filter out the util module, it's inspect function is special
      value.inspect !== exports.inspect &&
      // Also filter out any prototype objects using the circular check.
      !(value.constructor && value.constructor.prototype === value)) {
    var ret = value.inspect(recurseTimes, ctx);
    if (!isString(ret)) {
      ret = formatValue(ctx, ret, recurseTimes);
    }
    return ret;
  }

  // Primitive types cannot have properties
  var primitive = formatPrimitive(ctx, value);
  if (primitive) {
    return primitive;
  }

  // Look up the keys of the object.
  var keys = Object.keys(value);
  var visibleKeys = arrayToHash(keys);

  if (ctx.showHidden) {
    keys = Object.getOwnPropertyNames(value);
  }

  // IE doesn't make error fields non-enumerable
  // http://msdn.microsoft.com/en-us/library/ie/dww52sbt(v=vs.94).aspx
  if (isError(value)
      && (keys.indexOf('message') >= 0 || keys.indexOf('description') >= 0)) {
    return formatError(value);
  }

  // Some type of object without properties can be shortcutted.
  if (keys.length === 0) {
    if (isFunction(value)) {
      var name = value.name ? ': ' + value.name : '';
      return ctx.stylize('[Function' + name + ']', 'special');
    }
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    }
    if (isDate(value)) {
      return ctx.stylize(Date.prototype.toString.call(value), 'date');
    }
    if (isError(value)) {
      return formatError(value);
    }
  }

  var base = '', array = false, braces = ['{', '}'];

  // Make Array say that they are Array
  if (isArray(value)) {
    array = true;
    braces = ['[', ']'];
  }

  // Make functions say that they are functions
  if (isFunction(value)) {
    var n = value.name ? ': ' + value.name : '';
    base = ' [Function' + n + ']';
  }

  // Make RegExps say that they are RegExps
  if (isRegExp(value)) {
    base = ' ' + RegExp.prototype.toString.call(value);
  }

  // Make dates with properties first say the date
  if (isDate(value)) {
    base = ' ' + Date.prototype.toUTCString.call(value);
  }

  // Make error with message first say the error
  if (isError(value)) {
    base = ' ' + formatError(value);
  }

  if (keys.length === 0 && (!array || value.length == 0)) {
    return braces[0] + base + braces[1];
  }

  if (recurseTimes < 0) {
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    } else {
      return ctx.stylize('[Object]', 'special');
    }
  }

  ctx.seen.push(value);

  var output;
  if (array) {
    output = formatArray(ctx, value, recurseTimes, visibleKeys, keys);
  } else {
    output = keys.map(function(key) {
      return formatProperty(ctx, value, recurseTimes, visibleKeys, key, array);
    });
  }

  ctx.seen.pop();

  return reduceToSingleString(output, base, braces);
}


function formatPrimitive(ctx, value) {
  if (isUndefined(value))
    return ctx.stylize('undefined', 'undefined');
  if (isString(value)) {
    var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                             .replace(/'/g, "\\'")
                                             .replace(/\\"/g, '"') + '\'';
    return ctx.stylize(simple, 'string');
  }
  if (isNumber(value))
    return ctx.stylize('' + value, 'number');
  if (isBoolean(value))
    return ctx.stylize('' + value, 'boolean');
  // For some reason typeof null is "object", so special case here.
  if (isNull(value))
    return ctx.stylize('null', 'null');
}


function formatError(value) {
  return '[' + Error.prototype.toString.call(value) + ']';
}


function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {
  var output = [];
  for (var i = 0, l = value.length; i < l; ++i) {
    if (hasOwnProperty(value, String(i))) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          String(i), true));
    } else {
      output.push('');
    }
  }
  keys.forEach(function(key) {
    if (!key.match(/^\d+$/)) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          key, true));
    }
  });
  return output;
}


function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {
  var name, str, desc;
  desc = Object.getOwnPropertyDescriptor(value, key) || { value: value[key] };
  if (desc.get) {
    if (desc.set) {
      str = ctx.stylize('[Getter/Setter]', 'special');
    } else {
      str = ctx.stylize('[Getter]', 'special');
    }
  } else {
    if (desc.set) {
      str = ctx.stylize('[Setter]', 'special');
    }
  }
  if (!hasOwnProperty(visibleKeys, key)) {
    name = '[' + key + ']';
  }
  if (!str) {
    if (ctx.seen.indexOf(desc.value) < 0) {
      if (isNull(recurseTimes)) {
        str = formatValue(ctx, desc.value, null);
      } else {
        str = formatValue(ctx, desc.value, recurseTimes - 1);
      }
      if (str.indexOf('\n') > -1) {
        if (array) {
          str = str.split('\n').map(function(line) {
            return '  ' + line;
          }).join('\n').substr(2);
        } else {
          str = '\n' + str.split('\n').map(function(line) {
            return '   ' + line;
          }).join('\n');
        }
      }
    } else {
      str = ctx.stylize('[Circular]', 'special');
    }
  }
  if (isUndefined(name)) {
    if (array && key.match(/^\d+$/)) {
      return str;
    }
    name = JSON.stringify('' + key);
    if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
      name = name.substr(1, name.length - 2);
      name = ctx.stylize(name, 'name');
    } else {
      name = name.replace(/'/g, "\\'")
                 .replace(/\\"/g, '"')
                 .replace(/(^"|"$)/g, "'");
      name = ctx.stylize(name, 'string');
    }
  }

  return name + ': ' + str;
}


function reduceToSingleString(output, base, braces) {
  var numLinesEst = 0;
  var length = output.reduce(function(prev, cur) {
    numLinesEst++;
    if (cur.indexOf('\n') >= 0) numLinesEst++;
    return prev + cur.replace(/\u001b\[\d\d?m/g, '').length + 1;
  }, 0);

  if (length > 60) {
    return braces[0] +
           (base === '' ? '' : base + '\n ') +
           ' ' +
           output.join(',\n  ') +
           ' ' +
           braces[1];
  }

  return braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
}


// NOTE: These type checking functions intentionally don't use `instanceof`
// because it is fragile and can be easily faked with `Object.create()`.
function isArray(ar) {
  return Array.isArray(ar);
}
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 isObject(re) && objectToString(re) === '[object RegExp]';
}
exports.isRegExp = isRegExp;

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

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

function isError(e) {
  return isObject(e) &&
      (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 = require('./support/isBuffer');

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


function pad(n) {
  return n < 10 ? '0' + n.toString(10) : n.toString(10);
}


var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
              'Oct', 'Nov', 'Dec'];

// 26 Feb 16:19:34
function timestamp() {
  var d = new Date();
  var time = [pad(d.getHours()),
              pad(d.getMinutes()),
              pad(d.getSeconds())].join(':');
  return [d.getDate(), months[d.getMonth()], time].join(' ');
}


// log is just a thin wrapper to console.log that prepends a timestamp
exports.log = function() {
  console.log('%s - %s', timestamp(), exports.format.apply(exports, arguments));
};


/**
 * Inherit the prototype methods from one constructor into another.
 *
 * The Function.prototype.inherits from lang.js rewritten as a standalone
 * function (not on Function.prototype). NOTE: If this file is to be loaded
 * during bootstrapping this function needs to be rewritten using some native
 * functions as prototype setup using normal JavaScript does not work as
 * expected during bootstrapping (see mirror.js in r114903).
 *
 * @param {function} ctor Constructor function which needs to inherit the
 *     prototype.
 * @param {function} superCtor Constructor function to inherit prototype from.
 */
exports.inherits = require('inherits');

exports._extend = function(origin, add) {
  // Don't do anything if add isn't an object
  if (!add || !isObject(add)) return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
};

function hasOwnProperty(obj, prop) {
  return Object.prototype.hasOwnProperty.call(obj, prop);
}

}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./support/isBuffer":26,"_process":312,"inherits":25}],28:[function(require,module,exports){
'use strict'

exports.byteLength = byteLength
exports.toByteArray = toByteArray
exports.fromByteArray = fromByteArray

var lookup = []
var revLookup = []
var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array

var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
for (var i = 0, len = code.length; i < len; ++i) {
  lookup[i] = code[i]
  revLookup[code.charCodeAt(i)] = i
}

// Support decoding URL-safe base64 strings, as Node.js does.
// See: https://en.wikipedia.org/wiki/Base64#URL_applications
revLookup['-'.charCodeAt(0)] = 62
revLookup['_'.charCodeAt(0)] = 63

function getLens (b64) {
  var len = b64.length

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

  // Trim off extra bytes after placeholder bytes are found
  // See: https://github.com/beatgammit/base64-js/issues/42
  var validLen = b64.indexOf('=')
  if (validLen === -1) validLen = len

  var placeHoldersLen = validLen === len
    ? 0
    : 4 - (validLen % 4)

  return [validLen, placeHoldersLen]
}

// base64 is 4/3 + up to two characters of the original data
function byteLength (b64) {
  var lens = getLens(b64)
  var validLen = lens[0]
  var placeHoldersLen = lens[1]
  return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
}

function _byteLength (b64, validLen, placeHoldersLen) {
  return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
}

function toByteArray (b64) {
  var tmp
  var lens = getLens(b64)
  var validLen = lens[0]
  var placeHoldersLen = lens[1]

  var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen))

  var curByte = 0

  // if there are placeholders, only get up to the last complete 4 chars
  var len = placeHoldersLen > 0
    ? validLen - 4
    : validLen

  var i
  for (i = 0; i < len; i += 4) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 18) |
      (revLookup[b64.charCodeAt(i + 1)] << 12) |
      (revLookup[b64.charCodeAt(i + 2)] << 6) |
      revLookup[b64.charCodeAt(i + 3)]
    arr[curByte++] = (tmp >> 16) & 0xFF
    arr[curByte++] = (tmp >> 8) & 0xFF
    arr[curByte++] = tmp & 0xFF
  }

  if (placeHoldersLen === 2) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 2) |
      (revLookup[b64.charCodeAt(i + 1)] >> 4)
    arr[curByte++] = tmp & 0xFF
  }

  if (placeHoldersLen === 1) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 10) |
      (revLookup[b64.charCodeAt(i + 1)] << 4) |
      (revLookup[b64.charCodeAt(i + 2)] >> 2)
    arr[curByte++] = (tmp >> 8) & 0xFF
    arr[curByte++] = tmp & 0xFF
  }

  return arr
}

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

function encodeChunk (uint8, start, end) {
  var tmp
  var output = []
  for (var i = start; i < end; i += 3) {
    tmp =
      ((uint8[i] << 16) & 0xFF0000) +