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meirkl/base32-bitwise.js

Last active September 18, 2022 08:39
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Raw
base32-bitwise.js
function Base32(v) {
v = v?.toString();
if (!v || !v.length) {
throw new Error('Value must not be empty');
}
const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
let bits = 0;
let value = 0;
let base32 = '';
const data = Buffer.from(v);
for (let i = 0; i < data.length; i++) {
value = (value << 8) | data[i];
bits += 8;
while (bits >= 5) {
base32 += alphabet[(value >>> (bits - 5)) & 31];
bits -= 5;
}
}
if (bits > 0) {
base32 += alphabet[(value << (5 - bits)) & 31];
}
while (base32.length % 8 !== 0) {
base32 += '=';
}
return base32;
}
console.log(Base32('test'));
Raw
base32.js
function Base32(v) {
v = v?.toString();
if (!v || !v.length) {
throw new Error('Value must not be empty');
}
const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
const binaryArray = Array.from(v).map((c) => {
const ascii = c.charCodeAt(0);
let binary = ascii.toString(2);
binary = '0'.repeat(8).substring(binary.length) + binary;
return binary;
});
while (binaryArray.length % 5) {
binaryArray.push('x'.repeat(8));
}
const groups = binaryArray.join('').match(/.{1,5}/g);
const base32 = groups
.map((g) => {
if (g === 'x'.repeat(5)) {
return '=';
}
const index = parseInt(g.replace(/x/g, '0'), 2);
return alphabet[index];
})
.join('');
return base32;
}
console.log(Base32('test'));
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