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35 lines
983 B
35 lines
983 B
2 weeks ago
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let random = async bytes => crypto.getRandomValues(new Uint8Array(bytes))
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let customAlphabet = (alphabet, defaultSize = 21) => {
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let mask = (2 << (Math.log(alphabet.length - 1) / Math.LN2)) - 1
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let step = -~((1.6 * mask * defaultSize) / alphabet.length)
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return async (size = defaultSize) => {
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let id = ''
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while (true) {
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let bytes = crypto.getRandomValues(new Uint8Array(step))
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let i = step
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while (i--) {
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id += alphabet[bytes[i] & mask] || ''
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if (id.length === size) return id
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}
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}
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}
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}
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let nanoid = async (size = 21) => {
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let id = ''
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let bytes = crypto.getRandomValues(new Uint8Array(size))
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while (size--) {
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let byte = bytes[size] & 63
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if (byte < 36) {
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id += byte.toString(36)
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} else if (byte < 62) {
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id += (byte - 26).toString(36).toUpperCase()
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} else if (byte < 63) {
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id += '_'
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} else {
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id += '-'
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}
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}
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return id
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}
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module.exports = { nanoid, customAlphabet, random }
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