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37 lines
1.1 KiB
37 lines
1.1 KiB
let { urlAlphabet } = require('./url-alphabet/index.cjs') |
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let random = bytes => crypto.getRandomValues(new Uint8Array(bytes)) |
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let customRandom = (alphabet, defaultSize, getRandom) => { |
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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 (size = defaultSize) => { |
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let id = '' |
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while (true) { |
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let bytes = getRandom(step) |
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let j = step |
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while (j--) { |
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id += alphabet[bytes[j] & 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 customAlphabet = (alphabet, size = 21) => |
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customRandom(alphabet, size, random) |
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let nanoid = (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, customRandom, urlAlphabet, random }
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