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/**
* An isomorphic, load-anywhere function to convert a bytes value into a more human-readable format. Choose between [metric or IEC units](https://en.wikipedia.org/wiki/Gigabyte), summarised below.
*
* Value | Metric
* ----- | -------------
* 1000 | kB kilobyte
* 1000^2 | MB megabyte
* 1000^3 | GB gigabyte
* 1000^4 | TB terabyte
* 1000^5 | PB petabyte
* 1000^6 | EB exabyte
* 1000^7 | ZB zettabyte
* 1000^8 | YB yottabyte
*
* Value | IEC
* ----- | ------------
* 1024 | KiB kibibyte
* 1024^2 | MiB mebibyte
* 1024^3 | GiB gibibyte
* 1024^4 | TiB tebibyte
* 1024^5 | PiB pebibyte
* 1024^6 | EiB exbibyte
* 1024^7 | ZiB zebibyte
* 1024^8 | YiB yobibyte
*
* Value | Metric (octet)
* ----- | -------------
* 1000 | ko kilooctet
* 1000^2 | Mo megaoctet
* 1000^3 | Go gigaoctet
* 1000^4 | To teraoctet
* 1000^5 | Po petaoctet
* 1000^6 | Eo exaoctet
* 1000^7 | Zo zettaoctet
* 1000^8 | Yo yottaoctet
*
* Value | IEC (octet)
* ----- | ------------
* 1024 | Kio kilooctet
* 1024^2 | Mio mebioctet
* 1024^3 | Gio gibioctet
* 1024^4 | Tio tebioctet
* 1024^5 | Pio pebioctet
* 1024^6 | Eio exbioctet
* 1024^7 | Zio zebioctet
* 1024^8 | Yio yobioctet
*
* @module byte-size
* @example
* ```js
* const byteSize = require('byte-size')
* ```
*/
class ByteSize {
constructor (bytes, options) {
options = options || {}
options.units = options.units || 'metric'
options.precision = typeof options.precision === 'undefined' ? 1 : options.precision
const table = [
{ expFrom: 0, expTo: 1, metric: 'B', iec: 'B', metric_octet: 'o', iec_octet: 'o' },
{ expFrom: 1, expTo: 2, metric: 'kB', iec: 'KiB', metric_octet: 'ko', iec_octet: 'Kio' },
{ expFrom: 2, expTo: 3, metric: 'MB', iec: 'MiB', metric_octet: 'Mo', iec_octet: 'Mio' },
{ expFrom: 3, expTo: 4, metric: 'GB', iec: 'GiB', metric_octet: 'Go', iec_octet: 'Gio' },
{ expFrom: 4, expTo: 5, metric: 'TB', iec: 'TiB', metric_octet: 'To', iec_octet: 'Tio' },
{ expFrom: 5, expTo: 6, metric: 'PB', iec: 'PiB', metric_octet: 'Po', iec_octet: 'Pio' },
{ expFrom: 6, expTo: 7, metric: 'EB', iec: 'EiB', metric_octet: 'Eo', iec_octet: 'Eio' },
{ expFrom: 7, expTo: 8, metric: 'ZB', iec: 'ZiB', metric_octet: 'Zo', iec_octet: 'Zio' },
{ expFrom: 8, expTo: 9, metric: 'YB', iec: 'YiB', metric_octet: 'Yo', iec_octet: 'Yio' }
]
const base = options.units === 'metric' || options.units === 'metric_octet' ? 1000 : 1024
const prefix = bytes < 0 ? '-' : '';
bytes = Math.abs(bytes);
for (let i = 0; i < table.length; i++) {
const lower = Math.pow(base, table[i].expFrom)
const upper = Math.pow(base, table[i].expTo)
if (bytes >= lower && bytes < upper) {
const units = table[i][options.units]
if (i === 0) {
this.value = prefix + bytes
this.unit = units
return
} else {
this.value = prefix + (bytes / lower).toFixed(options.precision)
this.unit = units
return
}
}
}
this.value = prefix + bytes
this.unit = ''
}
toString () {
return `${this.value} ${this.unit}`.trim()
}
}
/**
* @param {number} - the bytes value to convert.
* @param [options] {object} - optional config.
* @param [options.precision=1] {number} - number of decimal places.
* @param [options.units=metric] {string} - select `'metric'`, `'iec'`, `'metric_octet'` or `'iec_octet'` units.
* @returns {{ value: string, unit: string}}
* @alias module:byte-size
* @example
* ```js
* > const byteSize = require('byte-size')
*
* > byteSize(1580)
* { value: '1.6', unit: 'kB' }
*
* > byteSize(1580, { units: 'iec' })
* { value: '1.5', unit: 'KiB' }
*
* > byteSize(1580, { units: 'iec', precision: 3 })
* { value: '1.543', unit: 'KiB' }
*
* > byteSize(1580, { units: 'iec', precision: 0 })
* { value: '2', unit: 'KiB' }
*
* > byteSize(1580, { units: 'metric_octet' })
* { value: '1.6', unit: 'ko' }
*
* > byteSize(1580, { units: 'iec_octet' })
* { value: '1.5', unit: 'Kio' }
*
* > byteSize(1580, { units: 'iec_octet' }).toString()
* '1.5 Kio'
*
* > const { value, unit } = byteSize(1580, { units: 'iec_octet' })
* > `${value} ${unit}`
* '1.5 Kio'
* ```
*/
function byteSize (bytes, options) {
return new ByteSize(bytes, options)
}
export default byteSize
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