Lightweight application memory cache-revalidate with minimal retry/fallback strategy

 

Npm installation

$ npm install cache-puppy

Basic Usage

import { CachePuppy } from 'cache-puppy';
import axios from 'axios';

const fetchPets = async (): Promise<IPet[]> => {
  return (await axios.get('www.pets/api/puppies')).data;
};

// cached pets with revalidation every 5 minutes
const cache = new CachePuppy<IPet[]>({
  initialData: fetchPets,
  revalidateFn: fetchPets,
  fallbackFn: [
    { petId: 23, name: 'bulldog' },
    { petId: 18, name: 'yorkshire terrier' },
  ],
  revalidateOpts: {
    retries: 5,
    interval: 1000 * 60 * 5, // 5 mins
  },
});

// some time later
console.log(cache.get()); // cached pets

Basic Features

• Simple to the point interface
• Linear and exponential retry strategies
• Provides custom Initial data, Revalidate and Fallback resolvers
• Allows plugging in custom cache setters/getters (can be useful for using other in memory caching connectors e.g Redis, Memcached)

API

CachePuppy(options: CacheOpts)

methods

Property	Type	description
get	() => T	gets cache value
set	(data: T) => Promise<void>	sets cache value
revalidate	() => Promise< void >	revalidates cache
teardown	() => void	gracfully tears down cache

CacheOpts

An object type representing cache options

properties

Property	Type	description	default
initialData?	(() => T | Promise< T >) | T	initial cache data or a function to be resolved from	undefined
revalidateFn?	(() => T | Promise< T >) | T	revalidation data or a function to be resolved from	undefined
fallBackFn?	(() => T | Promise< T >) | T	fallback value or a function to be resolved from	undefined
getterFn?	() => T | undefined	custom cache getter function	undefined
setterFn?	(data) => void	custom cache setter function	undefined
revalidateOpts?	RevalidateOpts	revalidation options	defaultCacheOptions.revalidateOpts

RevalidateOpts

An object cache revalidation options

properties

Property	Type	description	default
strategy?	linear | exponential	cache retry strategy	linear
interval?	number	cache revalidation interval (ms)	6000 (1 min)
backOff?	number	retry backoff time (ms)	300
exponentialBackoff?	number	retry exponential backoff time (ms) (for exponential strategy)	10
retries	number	number of maximum retries	3
onSuccess	(cache) => Promise< void > | void	callback on revalidation success	undefined
onRetriesReached	(cache, err) => Promise< void > | void	callback on maximum retries reached	undefined

Todo

• async getterFn/setterFn
• tests