Huge News!Announcing our $40M Series B led by Abstract Ventures.Learn More
Socket
Sign inDemoInstall
Socket

memory-cache-node

Package Overview
Dependencies
Maintainers
1
Versions
7
Alerts
File Explorer

Advanced tools

Socket logo

Install Socket

Detect and block malicious and high-risk dependencies

Install

memory-cache-node

Fast, modern and event loop non-blocking memory cache for Node.js and browse

  • 1.4.0
  • latest
  • Source
  • npm
  • Socket score

Version published
Weekly downloads
5.7K
increased by29.62%
Maintainers
1
Weekly downloads
 
Created
Source

memory-cache-node

version build coverage Quality Gate Status Bugs Vulnerabilities Downloads MIT License

A fast and type safe memory cache for Node.js and browser. memory-cache-node use Javascript Map as cache implementation which is faster than using Javascript object that some other similar libraries use. memory-cache-node also uses implementation that does not block the event loop for a long time, if the cache is very large (hundreds of thousands or millions of entries).

Table of Contents

Installation

npm install --save memory-cache-node

Usage

Creating a memory cache

Below example creates a memory cache for items which has string keys and number values. Memory cache checks expiring items every 600 seconds (i.e. every 10 minutes) The maximum number of items in the cache is 1 million.

import { MemoryCache } from 'memory-cache-node';

const itemsExpirationCheckIntervalInSecs = 10 * 60;
const maxItemCount = 1000000;
const memoryCache = new MemoryCache<string, number>(itemsExpirationCheckIntervalInSecs, maxItemCount);

Storing items in the memory cache

Below example stores a permanent item in the memory cache with key key1 and stores an expiring item with key key2. The latter item expires earliest after 30 minutes.

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);

const timeToLiveInSecs = 30 * 60;
memoryCache.storeExpiringItem('key2', 2, timeToLiveInSecs);

Getting the number of items in the memory cache

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);

const timeToLiveInSecs = 30 * 60;
memoryCache.storeExpiringItem('key2', 2, timeToLiveInSecs);
console.log(memoryCache.getItemCount()); // Logs to console: 2

Checking if an item exists in the memory cache

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);

console.log(memoryCache.hasItem('key1')); // Logs to console: true
console.log(memoryCache.hasItem('notFound')); // Logs to console: false

Retrieving the value of an item in the memory cache

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);

console.log(memoryCache.retrieveItemValue('key1')); // Logs to console: 1
console.log(memoryCache.retrieveItemValue('notFound')); // Logs to console: undefined

Getting the item expiration timestamp

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);

console.log(memoryCache.getItemExpirationTimestampInMillisSinceEpoch('key1')); // Logs some large number to console

Removing an item from the memory cache

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
memoryCache.storePermanentItem('key1', 1);
console.log(memoryCache.hasItem('key1')); // Logs to console: true
memoryCache.removeItem('key1');
console.log(memoryCache.hasItem('key1')); // Logs to console: false

Clearing the memory cache

Below examples removes all items from the memory cache

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
// Use cache here
// ...
memoryCache.clear()

Destroying the memory cache

Below example destroys the memory cache and it should not be used after that. It clears the memory cache and also removes the timer for checking expired items. NOTE! You should NEVER use a destroyed cache again! If you try to use a destroyed memory cache, an exception will be thrown. You should destroy your memory cache if it is not used in your application anymore.

import { MemoryCache } from 'memory-cache-node';

const memoryCache = new MemoryCache<string, number>(600, 1000000);
// Use cache here
// ...
memoryCache.destroy()

API Documentation

`K` is the type of the item key.
`V` is the type of the item value.
  
class MemoryCache<K, V> {
  constructor(itemsExpirationCheckIntervalInSecs: number, maxItemCount: number);
  storePermanentItem(itemKey: K, itemValue: V): void;
  storeExpiringItem(itemKey: K, itemValue: V, timeToLiveInSecs: number): void;
  getItemCount(): number;
  hasItem(itemKey: K): boolean;
  getValues(): V[];
  getItems(): [K, V][];
  retrieveItemValue(itemKey: K): V | undefined;
  getItemExpirationTimestampInMillisSinceEpoch(itemKey: K): number | undefined;
  removeItem(itemKey: K): void;
  exportItemsToJson(): string;
  
  // Use below function only with JSON output from exportItemsToJson method
  importItemsFrom(json: string): void; // Can throw if JSON is invalid
  
  clear(): void;
  destroy(): void;
}

License

MIT

Keywords

FAQs

Package last updated on 13 Nov 2022

Did you know?

Socket

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap
  • Changelog

Packages

npm

Stay in touch

Get open source security insights delivered straight into your inbox.


  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc