localforage-lru-driver

Localforage driver that maintains cache size depending on least-recently-used(lru) principle. localForage.

Requirements

• localforage v1.4.0+
• localforage-removeitems v1.4.0+
• localforage-indexes v1.0.2+

Installation

npm i localforage-lru-driver

Usage

Inserting into your project

import { extendPrototypeResult as localforage } from 'localforage-indexes';
import { lruDriver } from 'localforage-lru-driver';
 
localforage.defineDriver(lruDriver)
.then(function() {
  var lf = localforage.createInstance({
    driver    : 'lruStorage',
    cacheSize : 100
  });
 
  return lf.ready();
})
.then(function(lf) {
  // use localforage
})

When items count exceed cacheSize, least recently used item is removed:

// .... set items with keys KEY_1 ... KEY_100
 
lf.setItem('KEY_101', 'value')
.then(() => lf.length())
.then(length => console.log(length)) // 100
);

Each time an entry is accessed through getItem or setItem it is updated:

// .... set items with keys KEY_1 ... KEY_100. KEY_1 is set first
 
lf.getItem('KEY_1') // last access time updated
.then(() => lf.setItem('KEY_101', 'value'))
.then(length => console.log(length)) // 100
.then(() => lf.getItem('KEY_1'))
.then((key1Value) => console.log(key1Value)) // still present in the localforage

Contructor options

cacheSize

Maximum number of entries allowed to store Default value: 1000

lruKey

Name of the key that is used for keeping last access timestamp Default value: ACCESS_TIME

lruIndex

Name of the index that is used for sorting items by last access time Default value: lruIndex

Links

• GitHub
• NPM