cdk-amazon-chime-resources
Version:
21 lines (20 loc) • 861 B
JavaScript
import { alphabetByValue, bitsPerByte, bitsPerLetter, maxLetterValue } from "./constants.browser";
export function toBase64(input) {
let str = "";
for (let i = 0; i < input.length; i += 3) {
let bits = 0;
let bitLength = 0;
for (let j = i, limit = Math.min(i + 3, input.length); j < limit; j++) {
bits |= input[j] << ((limit - j - 1) * bitsPerByte);
bitLength += bitsPerByte;
}
const bitClusterCount = Math.ceil(bitLength / bitsPerLetter);
bits <<= bitClusterCount * bitsPerLetter - bitLength;
for (let k = 1; k <= bitClusterCount; k++) {
const offset = (bitClusterCount - k) * bitsPerLetter;
str += alphabetByValue[(bits & (maxLetterValue << offset)) >> offset];
}
str += "==".slice(0, 4 - bitClusterCount);
}
return str;
}