multiformats/cjs/src/bases/base32.js

Interface for multihash, multicodec, multibase and CID

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var base = require('./base.js');

function decode(input, alphabet) {
  input = input.replace(new RegExp('=', 'g'), '');
  const length = input.length;
  let bits = 0;
  let value = 0;
  let index = 0;
  const output = new Uint8Array(length * 5 / 8 | 0);
  for (let i = 0; i < length; i++) {
    value = value << 5 | alphabet.indexOf(input[i]);
    bits += 5;
    if (bits >= 8) {
      output[index++] = value >>> bits - 8 & 255;
      bits -= 8;
    }
  }
  return output;
}
function encode(buffer, alphabet) {
  const length = buffer.byteLength;
  const view = new Uint8Array(buffer);
  const padding = alphabet.indexOf('=') === alphabet.length - 1;
  if (padding) {
    alphabet = alphabet.substring(0, alphabet.length - 1);
  }
  let bits = 0;
  let value = 0;
  let output = '';
  for (let i = 0; i < length; i++) {
    value = value << 8 | view[i];
    bits += 8;
    while (bits >= 5) {
      output += alphabet[value >>> bits - 5 & 31];
      bits -= 5;
    }
  }
  if (bits > 0) {
    output += alphabet[value << 5 - bits & 31];
  }
  if (padding) {
    while (output.length % 8 !== 0) {
      output += '=';
    }
  }
  return output;
}
const base32 = base.withAlphabet({
  prefix: 'b',
  name: 'base32',
  alphabet: 'abcdefghijklmnopqrstuvwxyz234567',
  encode,
  decode
});
const base32pad = base.withAlphabet({
  prefix: 'c',
  name: 'base32pad',
  alphabet: 'abcdefghijklmnopqrstuvwxyz234567=',
  encode,
  decode
});
const base32hex = base.withAlphabet({
  prefix: 'v',
  name: 'base32hex',
  alphabet: '0123456789abcdefghijklmnopqrstuv',
  encode,
  decode
});
const base32hexpad = base.withAlphabet({
  prefix: 't',
  name: 'base32hexpad',
  alphabet: '0123456789abcdefghijklmnopqrstuv=',
  encode,
  decode
});
const base32z = base.withAlphabet({
  prefix: 'h',
  name: 'base32z',
  alphabet: 'ybndrfg8ejkmcpqxot1uwisza345h769',
  encode,
  decode
});

exports.base32 = base32;
exports.base32hex = base32hex;
exports.base32hexpad = base32hexpad;
exports.base32pad = base32pad;
exports.base32z = base32z;