A Simple Lightweight Pluggable Key-Value Cache For Multiple Storage Options.
npm install feather-cacheA Simple Pluggable Key-Value Cache For Multiple Storage Options.
``bash`
npm i --save feather-cache
You don't have to install type definitions for typescript. It's built in.
This is a simple caching frame which can be used with available drivers or you can easily write one your own. If no drivers are provided (default) works like an in-memory cache. But that is not what this module intended for. The in-memory cache is provided for the sake of convenience. If that is what all you want, lru-cache is recommended.
Actual use case for this module is to use with a driver (mongodb-driver or indexed-db-driver etc.) which enables persistent caching.
#### in memory cache
`ts
const { FeatherCache } = require('feather-cache');
// or
import { FeatherCache } from 'feather-cache';
// init
const fStore = new FeatherCache({
maxAgeInMs: 60 * 1000, // 1 min expiry
});
// ...async fn...
await fStore.set('hiya', 'mm!');
await fStore.get('hiya'); //-> mm!
await fStore.fetch('hiya'); //-> { key: 'hiya', val: 'mm!' }
// ... after expiry time
await fStore.get('hiya'); //-> null
`
#### with a driver
`ts`
// ...
const fStore = new FeatherCache(driver);
// ...
| function | description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| FeatherCache.set(key, val, opt) | returns Promise.key: stringval: any data to be stored opt: (optional) { maxAgeInMs: 1000 }, sets expiry time. |FeatherCache.get(key)
| | returns Promise which resolves to the stored data. else, null. null
If data has expired returns and then deletes the entry behind the scenes. |FeatherCache.fetch(key)
| | returns Promise which resolves to stored data. The difference between get and fetch is that, fetch returns the stored data one more time after its expiry and then deletes it.get
More info:: finds data -> if expired deletes it -> returns null.fetch: finds data -> if expired returns it -> and then deletes it.delete
However, you can control this behavior by passing the option (default delete: true). Eg: fStore.fetch('hiya', { delete: false }). This sets the expiry flag but don't delete it. Sometimes you may find this helpful. |FeatherCache.del(key)
| | returns Promise deletes the entry |
A driver is nothing but a configuration object which exposes a persistent storage interface.
`ts
const dbDriver = {
maxAgeInMs: 60 1000 5, // default expiry 5 mins
setFn: async function(key, val) {
// db interface to store data
await Db.create({ key, val });
},
getFn: async function(key) {
// db interface to get data
const data = await Db.find({ where: { key } });
return data;
},
delFn: async function(key) {
// db interface to delete data
await Db.remove({ where: { key } });
},
};
// pass in the driver
const featherStore = new FeatherCache(dbDriver);
// ...
`
An example: feather-cache-indexeddb.
Those who publish drivers advised to follow the naming convention:
`txt`
feather-cache-
Also, attach the key word feather-cache`.
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MIT © Vajahath Ahmed