32 lines
1.3 KiB
JavaScript
32 lines
1.3 KiB
JavaScript
import { decodeAscii, encodeLatin1 } from './latin1.js'
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import { decode2string } from './_utils.js'
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const ERR = 'percentEncodeSet must be a string of unique increasing codepoints in range 0x20 - 0x7e'
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const percentMap = new Map()
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let hex, base
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export function percentEncoder(set, spaceAsPlus = false) {
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if (typeof set !== 'string' || /[^\x20-\x7E]/.test(set)) throw new TypeError(ERR)
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if (typeof spaceAsPlus !== 'boolean') throw new TypeError('spaceAsPlus must be boolean')
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const id = set + +spaceAsPlus
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const cached = percentMap.get(id)
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if (cached) return cached
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const n = encodeLatin1(set).sort() // string checked above to be ascii
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if (decodeAscii(n) !== set || new Set(n).size !== n.length) throw new TypeError(ERR)
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if (!base) {
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hex = Array.from({ length: 256 }, (_, i) => `%${i.toString(16).padStart(2, '0').toUpperCase()}`)
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base = hex.map((h, i) => (i < 0x20 || i > 0x7e ? h : String.fromCharCode(i)))
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}
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const map = base.slice() // copy
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for (const c of n) map[c] = hex[c]
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if (spaceAsPlus) map[0x20] = '+' // overrides whatever percentEncodeSet thinks about it
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// Input is not typechecked, for internal use only
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const percentEncode = (u8, start = 0, end = u8.length) => decode2string(u8, start, end, map)
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percentMap.set(id, percentEncode)
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return percentEncode
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}
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