The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 'use strict';

 module.metadata = {

   'stability': 'experimental'

 };

 const method = require('../../method/core');

 const { uuid } = require('../util/uuid');

 // NOTE: use lang/functional memoize when it is updated to use WeakMap

 function memoize(f) {

   const memo = new WeakMap();

   return function memoizer(o) {

     let key = o;

     if (!memo.has(key))

       memo.set(key, f.apply(this, arguments));

     return memo.get(key);

   };

 }

 let identify = method('identify');

 identify.define(Object, memoize(function() { return uuid(); }));

 exports.identify = identify;