Rolling Storage

Rolling storage provides an API to localStorage and sessionStorage (or anything that implements the storage interface) that provides expiration and a maximum size.

Basic Usage

var rollingStorage = require('rolling-storage');
 
var storedItems = rollingStorage({
    namespace: 'my-items',
    ttl: 1000 * 60 * 60, // 1 hour
    maxSize: 1024 * 1024 * 1.5, // 1.5 MB
    storage: localStorage
})
 
// set
storedItems.set('thing1', 'hello!');
 
// access
storedItems.has('thing1'); // true
storedItems.get('thing1'); // 'hello!'
 
// remove
storedItems.remove('thing1');
 
// now it's gone
storedItems.has('thing1'); // false
storedItems.get('thing1'); // undefined
 

Creating an Instance

Each instance of rollingStorage has a namspace, a ttl, a maximum size, and must be provided with a storage strategy.

• namespace - This keeps instances of rollingStorage separate. Can be any string.
• ttl - The expiration time of values in milliseconds.
• maxSize - The max size of this namespace. Old elements will be removed when this limit is exceeded.
• storage - Probably localStorage or sessionStorage, but can be anything that implements the Storage API.

Using an Instace

Instance methods:

• instance.set(key, value) - sets a value. Value can be any type that can be run through JSON.stringify.
• instance.get(key) - gets a value from storage or undefined if the key doesn't exist.
• instance.has(key) - returns true if this key exists, false otherwise.
• instance.remove(key) - removes a key from storage.
• instance.flush() - removes all values from this instance.

Running The Tests

The tests were written with Jasmine and Testem.

1. npm install -g testem
2. testem
3. Open http://localhost:7357