File helper utilities for calculating file part ranges and generating part names. Useful for splitting large files into smaller chunks.

Install

• npm

  npm install --save @guanghechen/filepart

• yarn

  yarn add @guanghechen/filepart

Usage

Calculate File Parts by Size

Split a file into parts of a specific size:

import { calcFilePartItemsBySize } from '@guanghechen/filepart'

const fileSize = 1000 // bytes
const partSize = 300  // bytes per part

const parts = [...calcFilePartItemsBySize(fileSize, partSize)]
// Result:
// [
//   { sid: 1, start: 0, end: 300 },
//   { sid: 2, start: 300, end: 600 },
//   { sid: 3, start: 600, end: 900 },
//   { sid: 4, start: 900, end: 1000 }
// ]

Calculate File Parts by Count

Split a file into a specific number of parts:

import { calcFilePartItemsByCount } from '@guanghechen/filepart'

const fileSize = 1000 // bytes
const partCount = 3   // number of parts

const parts = [...calcFilePartItemsByCount(fileSize, partCount)]
// Result:
// [
//   { sid: 1, start: 0, end: 334 },
//   { sid: 2, start: 334, end: 668 },
//   { sid: 3, start: 668, end: 1000 }
// ]

Generate Part Names

Generate file part names with padded sequence numbers:

import { calcFilePartNames, calcFilePartNamesByCount } from '@guanghechen/filepart'

// From existing parts
const parts = [{ sid: 1 }, { sid: 2 }, { sid: 3 }]
const names = [...calcFilePartNames(parts, '.part')]
// Result: ['.part1', '.part2', '.part3']

// For 14 parts (with zero-padding)
const names14 = [...calcFilePartNamesByCount(14, '.part')]
// Result: ['.part01', '.part02', ... '.part14']

// Single part returns empty string (no suffix needed)
const singlePart = [...calcFilePartNamesByCount(1, '.part')]
// Result: ['']

Constants

import { DEFAULT_FILEPART_CODE_PREFIX } from '@guanghechen/filepart'

console.log(DEFAULT_FILEPART_CODE_PREFIX) // '.ghc-part'

Reference

• homepage