nxkit/hash/uuid.js

This is a collection of tools, independent of any other libraries

"use strict";
/* ***** BEGIN LICENSE BLOCK *****
 * Distributed under the BSD license:
 *
 * Copyright (c) 2015, xuewen.chu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of xuewen.chu nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL xuewen.chu BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ***** END LICENSE BLOCK ***** */
Object.defineProperty(exports, "__esModule", { value: true });
const util_1 = require("../util");
const buffer_1 = require("../buffer");
const rnds8 = buffer_1.default.alloc(16);
// Math.random()-based (RNG)
//
// If all else fails, use Math.random().  It's fast, but is of unspecified
// quality.
var _rng = function () {
    for (var i = 0, r = 0; i < 16; i++) {
        if ((i & 0x03) === 0)
            r = Math.random() * 0x100000000;
        rnds8[i] = r >>> ((i & 0x03) << 3) & 0xff;
    }
    return rnds8;
};
if (util_1.default.haveNode) { // node 
    const crypto = require('crypto');
    _rng = function () {
        return buffer_1.default.from(crypto.randomBytes(16));
    };
}
else if (util_1.default.haveWeb) {
    // Unique ID creation requires a high quality random # generator.  In the
    // browser this is a little complicated due to unknown quality of Math.random()
    // and inconsistent support for the `crypto` API.  We do the best we can via
    // feature-detection
    // getRandomValues needs to be invoked in a context where "this" is a Crypto
    // implementation. Also, find the complete implementation of crypto on IE11.
    let getRandomValues = (typeof (crypto) != 'undefined' &&
        crypto.getRandomValues && crypto.getRandomValues.bind(crypto)) ||
        (typeof (globalThis.msCrypto) != 'undefined' &&
            typeof globalThis.msCrypto.getRandomValues == 'function' &&
            globalThis.msCrypto.getRandomValues.bind(globalThis.msCrypto));
    if (getRandomValues) {
        // WHATWG crypto RNG - http://wiki.whatwg.org/wiki/Crypto
        // eslint-disable-line no-undef
        _rng = function () {
            return buffer_1.default.from(getRandomValues(rnds8));
        };
    }
}
function rng() {
    return _rng();
}
exports.rng = rng;
/**
 * Convert array of 16 byte values to UUID string format of the form:
 * XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
 */
var byteToHex = [];
for (var i = 0; i < 256; ++i) {
    byteToHex[i] = (i + 0x100).toString(16).substr(1);
}
function bytesToUuid(buf, offset) {
    var i = offset || 0;
    var bth = byteToHex;
    // join used to fix memory issue caused by concatenation: https://bugs.chromium.org/p/v8/issues/detail?id=3175#c4
    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++]]]).join('');
}
function uuid_v4(random) {
    var rnds = random || 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;
    return bytesToUuid(rnds);
}
exports.default = uuid_v4;