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// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
// deno-fmt-ignore
const base64abc = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L",
"M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "a",
"b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p",
"q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4",
"5", "6", "7", "8", "9", "+", "/"];
/**
* CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727
* Encodes a given Uint8Array, ArrayBuffer or string into RFC4648 base64 representation
* @param data
*/
export function encode(data: ArrayBuffer | string): string {
const uint8 =
typeof data === "string"
? new TextEncoder().encode(data)
: data instanceof Uint8Array
? data
: new Uint8Array(data);
let result = "",
i;
const l = uint8.length;
for (i = 2; i < l; i += 3) {
result += base64abc[uint8[i - 2] >> 2];
result += base64abc[((uint8[i - 2] & 0x03) << 4) | (uint8[i - 1] >> 4)];
result += base64abc[((uint8[i - 1] & 0x0f) << 2) | (uint8[i] >> 6)];
result += base64abc[uint8[i] & 0x3f];
}
if (i === l + 1) {
// 1 octet yet to write
result += base64abc[uint8[i - 2] >> 2];
result += base64abc[(uint8[i - 2] & 0x03) << 4];
result += "==";
}
if (i === l) {
// 2 octets yet to write
result += base64abc[uint8[i - 2] >> 2];
result += base64abc[((uint8[i - 2] & 0x03) << 4) | (uint8[i - 1] >> 4)];
result += base64abc[(uint8[i - 1] & 0x0f) << 2];
result += "=";
}
return result;
}
/**
* Decodes a given RFC4648 base64 encoded string
* @param b64
*/
export function decode(b64: string): Uint8Array {
const binString = atob(b64);
const size = binString.length;
const bytes = new Uint8Array(size);
for (let i = 0; i < size; i++) {
bytes[i] = binString.charCodeAt(i);
}
return bytes;
}
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