Press n or j to go to the next uncovered block, b, p or k for the previous block.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 2x 2x 2x 1x 3x 3x 1x 3x 3x 36x 36x 1x 10004x 10004x 100040x 100040x 1x 10002x 10002x 1x 1x 10002x 10002x 1x 1x 1x 1x 10002x 1x 8x | /* * Copyright 2016-2020 The NATS Authors * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ 'use strict' /** * Module Dependencies */ const crypto = require('crypto') /** * Constants */ const VERSION = '1.1.2' const digits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ' const base = 36 const preLen = 12 const seqLen = 10 const maxSeq = 3656158440062976 // base^seqLen == 36^10 const minInc = 33 const maxInc = 333 const totalLen = preLen + seqLen exports.version = VERSION /** * Create and initialize a nuid. * * @api private */ function Nuid () { this.buf = Buffer.alloc(totalLen) this.init() } /** * Initializes a nuid with a crypto random prefix, * and pseudo-random sequence and increment. * * @api private */ Nuid.prototype.init = function () { this.setPre() this.initSeqAndInc() this.fillSeq() } /** * Initializes the pseudo randmon sequence number and the increment range. * * @api private */ Nuid.prototype.initSeqAndInc = function () { this.seq = Math.floor(Math.random() * maxSeq) this.inc = Math.floor((Math.random() * (maxInc - minInc)) + minInc) } /** * Sets the prefix from crypto random bytes. Converts to base36. * * @api private */ Nuid.prototype.setPre = function () { const cbuf = crypto.randomBytes(preLen) for (let i = 0; i < preLen; i++) { const di = cbuf[i] % base this.buf[i] = digits.charCodeAt(di) } } /** * Fills the sequence part of the nuid as base36 from this.seq. * * @api private */ Nuid.prototype.fillSeq = function () { let n = this.seq for (let i = totalLen - 1; i >= preLen; i--) { this.buf[i] = digits.charCodeAt(n % base) n = Math.floor(n / base) } } /** * Returns the next nuid. * * @api private */ Nuid.prototype.next = function () { this.seq += this.inc if (this.seq > maxSeq) { this.setPre() this.initSeqAndInc() } this.fillSeq() return (this.buf.toString('ascii')) } /* Global Nuid */ const g = new Nuid() /** * Resets the prefix of the global nuid, as well as the * pseudo random sequence number and increment amounts. * * @api public */ exports.reset = function () { g.init() } /** * Returns the next nuid from the global. * * @api public */ exports.next = function () { return g.next() } /** * This here to facilitate testing * @api private */ exports.getGlobalNuid = function () { return g } |