You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
34 lines
1.0 KiB
34 lines
1.0 KiB
let { urlAlphabet } = require('./url-alphabet/index.cjs')
|
|
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
|
|
}, '')
|
|
module.exports = { nanoid, customAlphabet, customRandom, urlAlphabet, random }
|