basiccache.js

An extremely basic cache with a simple expiry system

Installation

npm install basiccache

Usage

first

node

var BasicCache = require('basiccache');

html

<script src="basiccache.min.js"></script>
<!-- // defines BasicCache() -->

then

var cache = new BasicCache();
 
cache.set('foo', 'bar');
// 'foo' will never expire
 
cache.set('key', 'value', 5 * 1000);
// key will expire in 5 seconds, regardless of access
 
cache.get('key');
// => 'value'
 
setTimeout(function() {
  cache.get('key');
  // => 'value'
}, 3 * 1000);
 
setTimeout(function() {
  cache.get('key');  // => undefined
  cache.get('foo');  // => 'bar'
}, 6 * 1000);
 

expiry can be set per individual key, or pass to constructor:

// default all keys to expire in one hour
var cache = new BasicCache({ expires: 3600 * 1000 })

Function

new BasicCache([opts])

• opts.debug: a function to use to print debug messages, defaults to a noop
• opts.expires: default expire time in ms
• opts.prefix: string to prefix the cache keys with for the internal cache object, defaults to basiccache_
• opts.purgeInterval: a time, in ms, to purge the cache of expired items, defaults to no timer

cache.get(key)

Returns the cached item if it exists and hasn't expired. If the item doesn't exist, or has been invalidated, this function will return undefined.

cache.set(key, value, [expires])

Set a key to a value, expires is the number of milliseconds from now when this specific cache entry expires. If not configured, and no opts.expires was set, the cache will never expire.

cache.remove(key)

Remove an entry from the cache, no errors are thrown if the key doesn't exist or is already invalidated.

cache.clear()

Remove all entries from the cache.

cache.purge()

Remove expired items from the cache.

cache.startTimer()

Start the timer for purging expired items.

cache.cancelTimer()

Stop the purge timer.

License

MIT