uuid.js

/*eslint no-bitwise: 0, eqeqeq: 0, curly: 0, strict: 0, no-eq-null: 0, no-shadow: 0, no-undef: 0 */
//		 uuid.js
//
//		 Copyright (c) 2010-2012 Robert Kieffer
//		 MIT License - http://opensource.org/licenses/mit-license.php
let uuid;
// Unique ID creation requires a high quality random # generator.	We feature
// detect to determine the best RNG source, normalizing to a function that
// returns 128-bits of randomness, since that's what's usually required
let _rng;

// Allow for MSIE11 msCrypto
let _crypto = window.crypto || window.msCrypto;

if (!_rng && _crypto && _crypto.getRandomValues) {
  // WHATWG crypto-based RNG - http://wiki.whatwg.org/wiki/Crypto
  //
  // Moderately fast, high quality
  let _rnds8 = new Uint8Array(16);
  _rng = function whatwgRNG() {
    _crypto.getRandomValues(_rnds8);
    return _rnds8;
  };
}

if (!_rng) {
  // Math.random()-based (RNG)
  //
  // If all else fails, use Math.random().	It's fast, but is of unspecified
  // quality.
  let _rnds = new Array(16);
  _rng = () => {
    for (let i = 0, r; i < 16; i++) {
      if ((i & 0x03) === 0) r = Math.random() * 0x100000000;
      _rnds[i] = (r >>> ((i & 0x03) << 3)) & 0xff;
    }

    return _rnds;
  };
}

// Buffer class to use
let BufferClass = typeof window.Buffer == 'function' ? window.Buffer : Array;

// Maps for number <-> hex string conversion
let _byteToHex = [];
let _hexToByte = {};
for (let i = 0; i < 256; i++) {
  _byteToHex[i] = (i + 0x100).toString(16).substr(1);
  _hexToByte[_byteToHex[i]] = i;
}

// **`parse()` - Parse a UUID into it's component bytes**
function parse(s, buf, offset) {
  let i = (buf && offset) || 0,
    ii = 0;

  buf = buf || [];
  s.toLowerCase().replace(/[0-9a-f]{2}/g, oct => {
    if (ii < 16) {
      // Don't overflow!
      buf[i + ii++] = _hexToByte[oct];
    }
  });

  // Zero out remaining bytes if string was short
  while (ii < 16) {
    buf[i + ii++] = 0;
  }

  return buf;
}

// **`unparse()` - Convert UUID byte array (ala parse()) into a string**
function unparse(buf, offset) {
  let i = offset || 0,
    bth = _byteToHex;
  return (
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]]
  );
}

// **`v1()` - Generate time-based UUID**
//
// Inspired by https://github.com/LiosK/UUID.js
// and http://docs.python.org/library/uuid.html

// random #'s we need to init node and clockseq
let _seedBytes = _rng();

// Per 4.5, create and 48-bit node id, (47 random bits + multicast bit = 1)
let _nodeId = [
  _seedBytes[0] | 0x01,
  _seedBytes[1],
  _seedBytes[2],
  _seedBytes[3],
  _seedBytes[4],
  _seedBytes[5]
];

// Per 4.2.2, randomize (14 bit) clockseq
let _clockseq = ((_seedBytes[6] << 8) | _seedBytes[7]) & 0x3fff;

// Previous uuid creation time
let _lastMSecs = 0,
  _lastNSecs = 0;

// See https://github.com/broofa/node-uuid for API details
function v1(options, buf, offset) {
  let i = (buf && offset) || 0;
  let b = buf || [];

  options = options || {};

  let clockseq = options.clockseq != null ? options.clockseq : _clockseq;

  // UUID timestamps are 100 nano-second units since the Gregorian epoch,
  // (1582-10-15 00:00).	JSNumbers aren't precise enough for this, so
  // time is handled internally as 'msecs' (integer milliseconds) and 'nsecs'
  // (100-nanoseconds offset from msecs) since unix epoch, 1970-01-01 00:00.
  let msecs = options.msecs != null ? options.msecs : new Date().getTime();

  // Per 4.2.1.2, use count of uuid's generated during the current clock
  // cycle to simulate higher resolution clock
  let nsecs = options.nsecs != null ? options.nsecs : _lastNSecs + 1;

  // Time since last uuid creation (in msecs)
  let dt = msecs - _lastMSecs + (nsecs - _lastNSecs) / 10000;

  // Per 4.2.1.2, Bump clockseq on clock regression
  if (dt < 0 && options.clockseq == null) {
    clockseq = (clockseq + 1) & 0x3fff;
  }

  // Reset nsecs if clock regresses (new clockseq) or we've moved onto a new
  // time interval
  if ((dt < 0 || msecs > _lastMSecs) && options.nsecs == null) {
    nsecs = 0;
  }

  // Per 4.2.1.2 Throw error if too many uuids are requested
  if (nsecs >= 10000) {
    throw new Error("uuid.v1(): Can't create more than 10M uuids/sec");
  }

  _lastMSecs = msecs;
  _lastNSecs = nsecs;
  _clockseq = clockseq;

  // Per 4.1.4 - Convert from unix epoch to Gregorian epoch
  msecs += 12219292800000;

  // `time_low`
  let tl = ((msecs & 0xfffffff) * 10000 + nsecs) % 0x100000000;
  b[i++] = (tl >>> 24) & 0xff;
  b[i++] = (tl >>> 16) & 0xff;
  b[i++] = (tl >>> 8) & 0xff;
  b[i++] = tl & 0xff;

  // `time_mid`
  let tmh = ((msecs / 0x100000000) * 10000) & 0xfffffff;
  b[i++] = (tmh >>> 8) & 0xff;
  b[i++] = tmh & 0xff;

  // `time_high_and_version`
  b[i++] = ((tmh >>> 24) & 0xf) | 0x10; // include version
  b[i++] = (tmh >>> 16) & 0xff;

  // `clock_seq_hi_and_reserved` (Per 4.2.2 - include variant)
  b[i++] = (clockseq >>> 8) | 0x80;

  // `clock_seq_low`
  b[i++] = clockseq & 0xff;

  // `node`
  let node = options.node || _nodeId;
  for (let n = 0; n < 6; n++) {
    b[i + n] = node[n];
  }

  return buf ? buf : unparse(b);
}

// **`v4()` - Generate random UUID**

// See https://github.com/broofa/node-uuid for API details
function v4(options, buf, offset) {
  // Deprecated - 'format' argument, as supported in v1.2
  let i = (buf && offset) || 0;

  if (typeof options == 'string') {
    buf = options == 'binary' ? new BufferClass(16) : null;
    options = null;
  }
  options = options || {};

  let rnds = options.random || (options.rng || _rng)();

  // Per 4.4, set bits for version and `clock_seq_hi_and_reserved`
  rnds[6] = (rnds[6] & 0x0f) | 0x40;
  rnds[8] = (rnds[8] & 0x3f) | 0x80;

  // Copy bytes to buffer, if provided
  if (buf) {
    for (let ii = 0; ii < 16; ii++) {
      buf[i + ii] = rnds[ii];
    }
  }

  return buf || unparse(rnds);
}

// Export public API
uuid = v4;
uuid.v1 = v1;
uuid.v4 = v4;
uuid.parse = parse;
uuid.unparse = unparse;
uuid.BufferClass = BufferClass;

// assign a unique id to this axe instance
axe._uuid = v1();

export { v1, v4, parse, unparse, BufferClass };
export default v4;