cache-dir.ts

Cache and re-use computation result with custom filename and directory.

Features

• Cache computation results with custom filenames and directories
• Configurable cache expiration interval
• Support for both asynchronous and synchronous operations
• TypeScript typings included out of the box

Installation

You can install this package using npm/pnpm/yarn/slnpm:

npm install cache-dir.ts

Typescript Signature

Type signature of the main class CacheDir

export type CacheDirOptions = {
  /** @default '.cache' */
  dir?: string

  /** @default 15*60*1000 (15 minutes) */
  expireInterval?: number

  /** @default '.gitignore' (false to skip auto append) */
  gitignore?: string | false
}

export class CacheDir {
  constructor(options?: CacheDirOptions)

  runSync(args: { filename: string; fn: () => string; as?: 'string' }): string
  runSync(args: { filename: string; fn: () => Buffer; as?: 'buffer' }): Buffer
  runSync(args: { filename: string; fn: () => string | Buffer }): string | Buffer

  runAsync(args: { filename: string; fn: () => Promise<string>; as?: 'string' }): Promise<string>
  runAsync(args: { filename: string; fn: () => Promise<Buffer>; as?: 'buffer' }): Promise<Buffer>
  runAsync(args: { filename: string; fn: () => Promise<string | Buffer> }): Promise<string | Buffer>
}

Type signature of helper function:

export function appendIgnoreLine(file: string, line: string): void;

Usage Example

Here is a basic example of how to use the CacheDir class:

import { CacheDir } from 'cache-dir.ts'

let cache = new CacheDir()

let result = cache.runSync({
  filename: 'task-1.txt',
  fn: () => 'version 1',
})

console.assert(result == 'version 1', 'task 1 should run')

result = cache.runSync({
  filename: 'task-1.txt',
  fn: () => 'version 2',
})

console.assert(result == 'version 1', 'task 1 should be cached')

License

This project is licensed with BSD-2-Clause

This is free, libre, and open-source software. It comes down to four essential freedoms [ref]:

• The freedom to run the program as you wish, for any purpose
• The freedom to study how the program works, and change it so it does your computing as you wish
• The freedom to redistribute copies so you can help others
• The freedom to distribute copies of your modified versions to others