@iohub/sizeinfo/index.js

Smart utilities for converting file sizes to human-readable formats with customizable decimal and binary scale conversions

import { roundD2 } from '@aryth/math';

function base3ToScale(base3, dec) {
  if (base3 === 0) return 'B'                //
  if (base3 === 1) return dec ? 'K' : 'KB' // Kilo
  if (base3 === 2) return dec ? 'M' : 'MB' // Mega
  if (base3 === 3) return dec ? 'G' : 'GB' // Giga
  if (base3 === 4) return dec ? 'T' : 'TB' // Tera
  if (base3 === 5) return dec ? 'P' : 'PB' // Peta
  if (base3 === 6) return dec ? 'E' : 'EB' // Exa
  if (base3 === 7) return dec ? 'Z' : 'ZB' // Zetta
  if (base3 === 8) return dec ? 'Y' : 'YB' // Yotta
}

/**
 * @param {number} num
 * @returns {string}
 */
function trailZero(num) {

  if (!num) return '0'
  const tx = '' + roundD2(num);
  let i = tx.indexOf('.');
  if (!~i) { return tx + '.00' }
  let df = tx.length - i;
  if (df === 3) { return tx }
  if (df === 2) { return tx + '0' }
  if (df === 1) { return tx + '00' }
  return tx
}

const humanScale = (num, dec) => {
  const B10 = dec ? 1000 : 1024;
  let base3 = 0;
  while (num > B10) { num /= B10, base3++; }
  return trailZero(num) + ' ' + base3ToScale(base3, dec)
};

export { base3ToScale, humanScale, trailZero };