Sma-cache

A simple memory cache with automatic invalidation after TTL. Runs on the browser and node

Installation

# npm
npm install sma-cache

# yarn
yarn add sma-cache

# pnpm
pnpm install sma-cache

Usage

import simpleCache from "sma-cache";

var TTL = 5000; // 5s
var cache = simpleCache(TTL);
var cacheItem = { greeting: "Hello World!" };
var key = "a-random-key";

cache.set(key, cacheItem);

The cacheItem will automatically invalidate after TTL, so that:

// using a delay mechanism
delay(TTL);
cache.get(key); // => undefined

Example

import simpleCache from "sma-cache";
import delay from "delay";

const cache = simpleCache(10);
function doSomething() {
  const now = Date.now();
  cache.set("time", now);
  // after 0 s
  delay(0).then(() => {
    console.log(cache.get("time")); //=> now
  });
  // after 5 s
  delay(5000).then(() => {
    console.log(cache.get("time")); //=> now
  });
  // after 10 s
  delay(10000).then(() => {
    console.log(cache.get("time")); //=> undefined
  });
}

doSomething();

API

simpleCache(ttl)

Returns a cache object which exposes methods to interact with the cache

ttl

Time in milliseconds before the item stored with key: random-key is invalidated

Type: number
Default: 6000

Cache Object API

The cache object exposes the following API

• set(key, options): store an item in the cache
  • key: the key for the cache item
    Type: string
    Required: true
  • options
    • ttl: Set a custom ttl for a cache item
      Type: number
      Default: global ttl
• get(key): get a cache item
  • key: the key for the cache item
    Type: string
    Required: true
• unset(key): remove an item from the cache
  • key: the key for the cache item
    Type: string
    Required: true
• hasKey(key): check if item with key exist in cache
  • key: the key for the cache item
    Type: string
    Required: true