co-cache

co-cache

Cache result in redis for AsyncFunction.

$3

``bash
$ npm i co-cache --save
`

$3

`js
const cache = require('co-cache')(defaultConfig);
cache(fn[, options]) => AsyncFunction
`

defaultConfig {Object}:
options {Object|Number->expire}:

- client: {Object} redis client of ioredis.
- prefix: {String} prefix for redis cache, default ''.
- key: {String|Function|AsyncFunction} prefix + key == cacheKey, default fn.name, if return false, skip get&set cache.
- expire: {Number} expire in ms.
- get: {Function|AsyncFunction} function to get cache.
- set: {Function|AsyncFunction} function to set cache.
- redisOpt: {Object} others options see ioredis

$3

`sh
$ DEBUG=co-cache node example.js
`

`js
process.env.DEBUG = 'co-cache'

const cache = require('.')({
prefix: 'cache:',
expire: 10 60 1000 // default expire
})

;(async function () {
const someAsyncFn = cache(async function someAsyncFn (number) {
console.log(someAsyncFn: ${number})
return number
}, {
key: function (number) {
if (number >= 4) {
return false // only cache when number < 4
}
return this.name + ':' + number
}
})

await someAsyncFn(1)
await someAsyncFn(2)
await someAsyncFn(2) // get from cache

await someAsyncFn.get(3)
await someAsyncFn.set(3, 'some value') // manually set cache
await someAsyncFn.get(3) // get from cache

await someAsyncFn(4) // not cache
await someAsyncFn.raw(5) // skip cache

await someAsyncFn.clear(1) // clear cache
await someAsyncFn.clear(2) // clear cache
await someAsyncFn.clear(3) // clear cache
await someAsyncFn.clear(4) // no effect, because there is no cache
})().catch(console.error)
`

$3

`js
function defaultGet (redis, cacheKey) {
return redis
.get(cacheKey)
.then((result) => {
if (result != null) {
return JSON.parse(result)
}
})
.catch(() => {})
}

function defaultSet (redis, cacheKey, result, ms) {
// cannot save undefined` value, null is ok
if (result === undefined) {
return
}
return redis
.set(cacheKey, JSON.stringify(result), 'PX', ms)
.catch(() => {})
}
`

$3

`
$ npm run test
``

$3

MIT