A simple to use cache for async-functions
npm install await-cacheA cache for async-functions. It also works for non-async functions. It's even possible to enable a LRU-algorithm.
``bash`
npm i await-cache
Simply surround the async function you want to cache. In this example fetch is a function that loads a file.`js
const cachify = require('await-cache');
const cachedFetch = cachify(/ function to cache: /fetch, / cache-time in milliseconds: / 1000 60 60)
async function test() {
try {
const data1 = await cachedFetch('foo.bar') // will do the real fetch and cache it for an hour
const data2 = await cachedFetch('foo.bar') // will instantly return the cached value
const data3 = await cachedFetch('foo2.bar') // will fetch a different result and cache it for an hour
} catch(e) {
// fetch throw an error
console.error(e)
}
}
`
Second argument can be the cache-time in milliseconds or an object of options. With setting the maxSize-option you enable the LRU-Cache:
`js
const cachify = require('await-cache');
const cachedFunc = cachify(async (filename) => {
let data = await fetch(filename)
return JSON.parse(data)
}, {
maxAge: 60 60 1000, // cache for an hour
maxSize: 2, // enable LRU-cache. Only cache the last 2 used files. The cache will never save more that the result of 2 different arguments.
serialize: (args) => JSON.stringify(args) // use a special argument-serialize-function
})
`
The default serialisation for the arguments uses JSON.stringify`. So you will have to write a custom serialisation if you want to use functions or complex objects as arguments.