doublecache v1.0.3

doublecache

what is it?

A hashmap-based disk cache, accelerated by a simple Map cache.
includes a convenient wrapper function, cacheify, to get a cached, async version of the same function(more below)
Memory cache uses LRU for eviction
Disk-cache allows safe concurrent operations for better performance
cache items include a creation time, allowing you to specify a max age for retrieved items

who is it aimed at?

probably not those looking for absolute highest performance. While this lib does aim to get good performance, its main goal is for caching expensive calls/functions where waiting for disk reads/writes is preferable

using it

install

npm i doublecache

wrapping a function

all wrapped functions will become async

import { cacheify } from 'doublecache'

function slowFunction(parameter) {
    // some very slow logic:
    // .
    // .
    // .

    console.log(parameter)
}

const wrapped = cacheify(slowFunction)

console.log(await wrapped('test1')) // the first call will be as slow as usual

console.log(await wrapped('test1')) // the next call will be fast, as it is in the cache

console.log(await wrapped('test2')) // this will be slow again as we dont have a cached result with this parameter

// lets try with test1 again, but we dont want a result older than 5s
// this will call slowFunction again if it has been more than 5s since the last call to wrapped('test1')
const returned = await wrapped.config{maxAge: 5 * 1000})('test1') 

setting and getting a key manually

import doublecache from 'doublecache'

await doublecache.set('key a', 'value a: values can be of any type')

console.log(await doublecache.get('key a'))  // logs  'value a: values can be of any type'

console.log(await doublecache.get('unused key'))  // logs  undefined