7820380e
 “wangming”
1
|
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
|
import { urlAlphabet } from './url-alphabet/index.js'
let random = bytes => crypto.getRandomValues(new Uint8Array(bytes))
let customRandom = (alphabet, defaultSize, getRandom) => {
let mask = (2 << (Math.log(alphabet.length - 1) / Math.LN2)) - 1
let step = -~((1.6 * mask * defaultSize) / alphabet.length)
return (size = defaultSize) => {
let id = ''
while (true) {
let bytes = getRandom(step)
let j = step
while (j--) {
id += alphabet[bytes[j] & mask] || ''
if (id.length === size) return id
}
}
}
}
let customAlphabet = (alphabet, size = 21) =>
customRandom(alphabet, size, random)
let nanoid = (size = 21) =>
crypto.getRandomValues(new Uint8Array(size)).reduce((id, byte) => {
byte &= 63
if (byte < 36) {
id += byte.toString(36)
} else if (byte < 62) {
id += (byte - 26).toString(36).toUpperCase()
} else if (byte > 62) {
id += '-'
} else {
id += '_'
}
return id
}, '')
export { nanoid, customAlphabet, customRandom, urlAlphabet, random }
|
