30 lines
1.2 KiB
TypeScript
30 lines
1.2 KiB
TypeScript
const _b64chars: string[] = [...'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/']
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const _mkUriSafe = (src: string): string => src.replace(/[+/]/g, (m0: string) => (m0 === '+' ? '-' : '_')).replace(/=+\$/m, '')
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const fromUint8Array = (src: Uint8Array, rfc4648 = false): string => {
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let b64 = ''
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for (let i = 0, l = src.length; i < l; i += 3) {
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const [a0, a1, a2] = [src[i], src[i + 1], src[i + 2]]
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const ord = (a0 << 16) | (a1 << 8) | a2
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b64 += _b64chars[ord >>> 18]
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b64 += _b64chars[(ord >>> 12) & 63]
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b64 += typeof a1 !== 'undefined' ? _b64chars[(ord >>> 6) & 63] : '='
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b64 += typeof a2 !== 'undefined' ? _b64chars[ord & 63] : '='
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}
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return rfc4648 ? _mkUriSafe(b64) : b64
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}
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const _btoa: (s: string) => string =
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typeof btoa === 'function'
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? (s: string) => btoa(s)
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: (s: string) => {
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if (s.charCodeAt(0) > 255) {
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throw new RangeError('The string contains invalid characters.')
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}
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return fromUint8Array(Uint8Array.from(s, (c: string) => c.charCodeAt(0)))
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}
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const utob = (src: string): string => unescape(encodeURIComponent(src))
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export default function encode(src: string, rfc4648 = false): string {
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const b64 = _btoa(utob(src))
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return rfc4648 ? _mkUriSafe(b64) : b64
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}
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