zipnum

zipnum

This is a quick number to string packer that works like 'number to hex' convertions but with arbitrary base/radix and alphabets, that defaults to 0...z...Z with base 62 that allows to safely pack large numbers to small strings. Originally written for WebsocketPromisify lib

This is needed when you want to put numbers into strings to use all encoding bits instead of leaving most of them as copies: '564654987' vs 'MnoIF' for example. With large quantities of them being sent via network or saved into storage, it has difference.

The library is written in Typescript and has js-doc annotations.

Performance

According to jsben.ch tests on intel 12100 / DDR4-3200-16 @ firefox107:

• zipping of (each time) randomly generated numbers from 0 to 1e20 is around 6.5Mops/sec (850Kops with random generation).
• unzipping numbers of 5(big) and 10(extremely large) chars (that each loop regenerated) to numbers is like 34 Mops/sec (930kops with string generation)

API with examples

import { setABC, zipnum, unzipnum } from 'zipnum'

// importing and calling setABC is fully optional,
//   because it is already called with 62-length alphabet under the hood and ready.
// But you can call it with large utf-8 sequences to compress stronger.
// Argument is a new alphabet.
setABC('0123456789abcdefghijklmnopqrstuvwxyz')

const packedString0 = zipnum(0) // -> '0'
const packedString1 = zipnum(10) // -> 'a'
const packedString2 = zipnum(564654987) // -> 'aq9rtm'

setABC('abcdefghijklmnopqrstuvwxyz!@#$%^&*()_')
const packedString3 = zipnum(564654987) // -> 'jmgsu@'
const unpackedNumber = unzipnum(packedString3) // -> 564654987