JustNode

Simple cache system for Node.js.

npm install @jnode/cache

Basic Usage

Import JustCache

const Cacher = require('@jnode/cache');

Create a Cacher

const cache = new Cacher();

Class: Cacher

The main class for managing the cache.

Constructor

new Cacher(data = new Map(), timeout = 600000)

• data: An optional Map object to initialize the cache with existing data. Default is a new Map().
• timeout: An optional number representing the default timeout (in milliseconds) for cached items. Default is 600000 (10 minutes). Set to 0 to make data cache forever.

Methods

• set(id, value): Sets or creates a new cache entry.
  • id: The ID of the cache entry.
  • value: The value to be cached.
  • Returns: The value that was just set.
  • Example:

  cache.set('user123', { name: 'Alice', age: 30 });

• edit(id, value): Edits an existing cache entry if the entry exists.
  • id: The ID of the cache entry.
  • value: The new value to be cached.
  • Returns: The value that was just set, or undefined if the entry does not exist.
  • Example:

  cache.edit('user123', { name: 'Alice', age: 31 });

• check(id): Checks if a cache entry exists.
  • id: The ID of the cache entry.
  • Returns: true if the entry exists, false otherwise.
  • Example:

  if (cache.check('user123')) {
      console.log('User data is cached!');
  }

• async get(id, ifNone): Gets a cache entry, or fetches it if it does not exist.
  • id: The ID of the cache entry.
  • ifNone: An async function that will be called with the id if the entry does not exist. The return value of this function will be set as the cached value.
  • Returns: A Promise that resolves to the cached value.
  • Example:

  async function fetchUserData(userId) {
      // Simulating fetching user data
      return new Promise(resolve => {
          setTimeout(() => {
            resolve({ name: 'Bob', age: 25 });
          }, 1000);
      });
  }
  
  cache.get('user456', fetchUserData).then(userData => {
      console.log('User data:', userData);
  });

• setTimeout(id): Sets or resets the timeout for a cache entry. You usually don't need to call this manually, as set, edit and get will auto call it.
  • id: The ID of the cache entry.
• clearTimeout(id): Clears the timeout for a cache entry, preventing it from being automatically deleted.
  • id: The ID of the cache entry.
  • Example:

  cache.clearTimeout('user123');