Memoize the last result, in async way.
async-memoize-one simply remembers the last arguments, and if the function is next called with the same arguments then it returns the previous result.
It's used for micro-caching scenarios, where you want to prevent perform an action previously done during a short period of time.
No need to worry about cache busting mechanisms such as maxAge, maxSize, exclusions and so on which can be prone to memory leaks.
Install
$ npm install async-memoize-one --save
Usage
const get = require('util').promisify(require('simple-get'))
const memoizeOne = require('async-memoize-one')
const fetchData = memoizeOne(url => get(`https://api.microlink.io?url=${url}`))
;(async () => {
// fecthing data for first time
console.time('fetch')
await fetchData('https://example.com/one')
console.timeEnd('fetch')
// served data from cache; no fetching!
console.time('fetch')
await fetchData('https://example.com/one')
console.timeEnd('fetch')
// previous execution parameters are different, so fetching again
console.time('fetch')
await fetchData('https://example.com/two')
console.timeEnd('fetch')
// previous execution parameters are different, so fetching again
console.time('fetch')
await fetchData('https://example.com/one')
console.timeEnd('fetch')
})()
API
memoizeOne(fn, [isEqual], [options])
fn
Required
Type: function
Promise-returning or async function to be memoized.
isEqual
Type: function
Default: fast-deep-equal
The compare function to determinate if both executions are the same.
An equality function should return true if the arguments are equal. If true is returned then the wrapped function will not be called.
options
cachePromiseRejection
Type: boolean
Default: false
Cache rejected promises.
License
async-memoize-one © microlink.io, released under the MIT License.
Authored and maintained by Kiko Beats with help from contributors.
microlink.io · GitHub microlink.io · Twitter @microlinkhq
