zkt-loader

cache data resource with smart auto-refresh and lock.

Usage

new ZKTLoader(name, loadFunction, options)

const ZKTLoader = require('zkt-loader');
const loader = new ZKTLoader('user', function(user_id) {
    return db.getUser(user_id);
}, {
    useRedis: true,
    redisOptions: 'redis://127.0.0.1:6379' //options passed to ioredis
});

//...

router.get('/getUser', async ctx => {
    ctx.body = loader.load(ctx.query.user_id);
});

//...

options

{
    //use redis? if not, use in-memory cache provided by node-cache
    useRedis: false, 

    //parameter passed to new IORedis()
    redisOptions: process.env.REDIS_URL,

    //use existing ioredis instance?
    redisInstance: null,

    //default expiration seconds
    //if you request data after this time, zkt-loader will return cached  
    //data immediately, then request real data to update cache in background
    ttl: 30,

    //prefix for every key
    keyPrefix: 'zktLoader'
}

cacheable decorator

require('zkt-loader').cacheable(name, options)(loadFunction)

example:

const { cacheable } = require('zkt-loader');

async function getName(id) {
    console.log('real getting name: ' + id);
    return 'foo' + id;
}
getName = cacheable('name', { ttl: 3 })(getName);

getName(1).then(console.log);
getName(1).then(console.log);