| import crypto from 'crypto' | |
| import { urlAlphabet } from '../url-alphabet/index.js' | |
| let random = bytes => | |
| new Promise((resolve, reject) => { | |
| crypto.randomFill(Buffer.allocUnsafe(bytes), (err, buf) => { | |
| if (err) { | |
| reject(err) | |
| } else { | |
| resolve(buf) | |
| } | |
| }) | |
| }) | |
| let customAlphabet = (alphabet, defaultSize = 21) => { | |
| let mask = (2 << (31 - Math.clz32((alphabet.length - 1) | 1))) - 1 | |
| let step = Math.ceil((1.6 * mask * defaultSize) / alphabet.length) | |
| let tick = (id, size = defaultSize) => | |
| random(step).then(bytes => { | |
| let i = step | |
| while (i--) { | |
| id += alphabet[bytes[i] & mask] || '' | |
| if (id.length === size) return id | |
| } | |
| return tick(id, size) | |
| }) | |
| return size => tick('', size) | |
| } | |
| let nanoid = (size = 21) => | |
| random(size).then(bytes => { | |
| let id = '' | |
| while (size--) { | |
| id += urlAlphabet[bytes[size] & 63] | |
| } | |
| return id | |
| }) | |
| export { nanoid, customAlphabet, random } | |