43 lines
1.2 KiB
JavaScript
43 lines
1.2 KiB
JavaScript
// This alphabet uses a-z A-Z 0-9 _- symbols.
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// Symbols are generated for smaller size.
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// -_zyxwvutsrqponmlkjihgfedcba9876543210ZYXWVUTSRQPONMLKJIHGFEDCBA
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var url = '-_'
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// Loop from 36 to 0 (from z to a and 9 to 0 in Base36).
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var i = 36
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while (i--) {
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// 36 is radix. Number.prototype.toString(36) returns number
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// in Base36 representation. Base36 is like hex, but it uses 0–9 and a-z.
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url += i.toString(36)
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}
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// Loop from 36 to 10 (from Z to A in Base36).
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i = 36
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while (i-- - 10) {
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url += i.toString(36).toUpperCase()
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}
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/**
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* Generate URL-friendly unique ID. This method use non-secure predictable
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* random generator with bigger collision probability.
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*
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* @param {number} [size=21] The number of symbols in ID.
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*
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* @return {string} Random string.
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*
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* @example
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* const nanoid = require('nanoid/non-secure')
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* model.id = nanoid() //=> "Uakgb_J5m9g-0JDMbcJqL"
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*
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* @name nonSecure
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* @function
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*/
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module.exports = function (size) {
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var id = ''
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i = size || 21
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// Compact alternative for `for (var i = 0; i < size; i++)`
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while (i--) {
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// `| 0` is compact and faster alternative for `Math.floor()`
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id += url[Math.random() * 64 | 0]
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}
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return id
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}
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