Cache Lib

Cache

Small lib (only 1.1kB gzipped and minified) which provides a key/value pair storage.

You can use it like a simple cache mechanism but you can also limit the size of the storage, set an expiry date, or bind the storage to the localStorage or the sessionStorage.

Support

This code works with nodejs and has been tested on the following browsers:

• Microsoft Internet Explorer for Windows, version 6.0 and higher
• Mozilla Firefox 1.0 and higher
• Apple Safari 2.0.4 and higher
• Opera 9.25 and higher
• Chrome 1.0 and higher

Documentation

Examples

// limit
var cache = new Cache({ limit: 3 });
cache.setItem('1', 'pear')
    .setItem('2', 'apple')
    .setItem('3', 'banana');

cache.length;      /* => 3            */
cache.getItem(1);  /* => 'pear'       */
cache.getItem(3);  /* => 'banana'     */
    
cache.setItem('4', 'strawberry');
cache.length;      /* => 3             */
cache.getItem(1);  /* => undefined    */
cache.getItem(2)]; /* => 'strawberry' */

var oneMinute = 1 * 60 * 60;

// localStorage binding + maxAge & expires options
var localCache = new Cache({ storage: localStorage, maxAge: oneMinute });
localCache.setItem(1, 'pear');
localCache.setItem(2, 'apple', { expires: new Date(+new Date() + 2 * oneMinute) });
localCache.setItem(3, 'banana', { maxAge: 3 * oneMinute });

localCache.length;     /* => 3 */
setTimeout(function() { localCache.length; /* => 2 */ }, oneMinute + 10);
setTimeout(function() { localCache.length; /* => 1 */ }, 2 * oneMinute + 10);
setTimeout(function() { localCache.length; /* => 0 */ }, 3 * oneMinute + 10);

/* If you use a persistent storage (like localStorage or sessionStorage), expires 
and maxAge options will do their jobs even if you refresh your browser */

/* Example: (set keyPrefix to avoid conflicts between cache instances) */
var localCache = new Cache({ storage: localStorage, keyPrefix: 'test' });
localCache.setItem(1, 'orange', { maxAge: oneMinute });

/* Now, refresh your browser, and: */
var localCache = new Cache({ storage: localStorage, keyPrefix: 'test' });
localCache.getItem(1); /* => 'orange' */
setTimeout(function() { localCache.length; /* => 0 */ }, oneMinute + 10);