cuid/dist/cuid.js

Collision-resistant ids optimized for horizontal scaling and performance. For node and browsers.

(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.cuid = 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){
/**
 * cuid.js
 * Collision-resistant UID generator for browsers and node.
 * Sequential for fast db lookups and recency sorting.
 * Safe for element IDs and server-side lookups.
 *
 * Extracted from CLCTR
 *
 * Copyright (c) Eric Elliott 2012
 * MIT License
 */

var fingerprint = require('./lib/fingerprint.js');
var pad = require('./lib/pad.js');
var getRandomValue = require('./lib/getRandomValue.js');

var c = 0,
  blockSize = 4,
  base = 36,
  discreteValues = Math.pow(base, blockSize);

function randomBlock () {
  return pad((getRandomValue() *
    discreteValues << 0)
    .toString(base), blockSize);
}

function safeCounter () {
  c = c < discreteValues ? c : 0;
  c++; // this is not subliminal
  return c - 1;
}

function cuid () {
  // Starting with a lowercase letter makes
  // it HTML element ID friendly.
  var letter = 'c', // hard-coded allows for sequential access

    // timestamp
    // warning: this exposes the exact date and time
    // that the uid was created.
    timestamp = (new Date().getTime()).toString(base),

    // Prevent same-machine collisions.
    counter = pad(safeCounter().toString(base), blockSize),

    // A few chars to generate distinct ids for different
    // clients (so different computers are far less
    // likely to generate the same id)
    print = fingerprint(),

    // Grab some more chars from Math.random()
    random = randomBlock() + randomBlock();

  return letter + timestamp + counter + print + random;
}

cuid.slug = function slug () {
  var date = new Date().getTime().toString(36),
    counter = safeCounter().toString(36).slice(-4),
    print = fingerprint().slice(0, 1) +
      fingerprint().slice(-1),
    random = randomBlock().slice(-2);

  return date.slice(-2) +
    counter + print + random;
};

cuid.isCuid = function isCuid (stringToCheck) {
  if (typeof stringToCheck !== 'string') return false;
  if (stringToCheck.startsWith('c')) return true;
  return false;
};

cuid.isSlug = function isSlug (stringToCheck) {
  if (typeof stringToCheck !== 'string') return false;
  var stringLength = stringToCheck.length;
  if (stringLength >= 7 && stringLength <= 10) return true;
  return false;
};

cuid.fingerprint = fingerprint;

module.exports = cuid;

},{"./lib/fingerprint.js":2,"./lib/getRandomValue.js":3,"./lib/pad.js":4}],2:[function(require,module,exports){
var pad = require('./pad.js');

var env = typeof window === 'object' ? window : self;
var globalCount = Object.keys(env).length;
var mimeTypesLength = navigator.mimeTypes ? navigator.mimeTypes.length : 0;
var clientId = pad((mimeTypesLength +
  navigator.userAgent.length).toString(36) +
  globalCount.toString(36), 4);

module.exports = function fingerprint () {
  return clientId;
};

},{"./pad.js":4}],3:[function(require,module,exports){

var getRandomValue;

var crypto = typeof window !== 'undefined' &&
  (window.crypto || window.msCrypto) ||
  typeof self !== 'undefined' &&
  self.crypto;

if (crypto) {
    var lim = Math.pow(2, 32) - 1;
    getRandomValue = function () {
        return Math.abs(crypto.getRandomValues(new Uint32Array(1))[0] / lim);
    };
} else {
    getRandomValue = Math.random;
}

module.exports = getRandomValue;

},{}],4:[function(require,module,exports){
module.exports = function pad (num, size) {
  var s = '000000000' + num;
  return s.substr(s.length - size);
};

},{}]},{},[1])(1)
});