level-js

What is level-js?

level-js is a JavaScript implementation of LevelDB for use in the browser. It provides a simple key-value store API that is compatible with the LevelUP interface, making it easy to use in conjunction with other LevelDB-based libraries.

What are level-js's main functionalities?

Basic Key-Value Store

This feature allows you to perform basic key-value operations such as putting, getting, and deleting data in the database.

const level = require('level-js');
const db = level('my-database');

// Put a value
await db.put('key', 'value');

// Get a value
const value = await db.get('key');
console.log(value); // 'value'

// Delete a value
await db.del('key');

Batch Operations

Batch operations allow you to perform multiple put and delete operations in a single atomic action, which can be more efficient than performing each operation individually.

const level = require('level-js');
const db = level('my-database');

// Perform batch operations
await db.batch()
  .put('key1', 'value1')
  .put('key2', 'value2')
  .del('key3')
  .write();

Stream API

The Stream API allows you to create readable and writable streams for iterating over the database entries, which is useful for processing large datasets.

const level = require('level-js');
const db = level('my-database');

// Create a read stream
const stream = db.createReadStream();

stream.on('data', ({ key, value }) => {
  console.log(key, value);
});

stream.on('end', () => {
  console.log('Stream ended');
});

Other packages similar to level-js

pouchdb

PouchDB is an open-source JavaScript database inspired by Apache CouchDB that is designed to run well within the browser. It provides a similar key-value store functionality but also includes advanced features like synchronization with CouchDB and other PouchDB instances.

localforage

LocalForage is a fast and simple storage library for JavaScript. It improves the offline experience of your web app by using asynchronous storage (IndexedDB or WebSQL) with a simple, localStorage-like API. It is more abstracted compared to level-js and is designed to be easier to use.

dexie

Dexie.js is a wrapper for IndexedDB that provides a more developer-friendly API. It offers advanced querying capabilities and transaction support, making it a powerful alternative to level-js for complex use cases.

README

level.js an implementation of the leveldown API on top of IndexedDB (which is in turn implemented on top of LevelDB, which brings this whole shebang full circle)

Most people use levelup on top of this library. See test-levelup.js for details

For some demos of it working, see @brycebaril's presentation "Path of the NodeBases Jedi": http://brycebaril.github.io/nodebase_jedi/#/vanilla

level.js uses IDBWrapper by jensarps to ensure compatibility between IDB implementations.

Here are the goals of this level.js:

• Store large amounts of ascii (strings, JSON) and binary (ArrayBuffers, Typed Arrays) data in modern browsers
• Be as fast as possible
• Use the leveldown test suite and sync with multilevel over either ascii or binary transports (websockets and xhr both have ascii/binary modes in browsers now)

Being leveldown compatible means you can use many of the level-* modules on top of this library.

install

npm install level-js

(Not to be confused with leveljs)

This library is best used with browserify

code examples

var leveljs = require('level-js')
var db = leveljs('bigdata')
db.open(function onOpen() { })

The test suite for this library is in the abstract-leveldown repo and is shared between various leveldown implementations across different environments and platforms.

For more code examples see the abstract-leveldown test suite

The only differences between this and leveldown is that you can store ArrayBuffers in this (whereas leveldown just uses node Buffer objects)

run the tests

git clone [e-mail]:maxogden/level.js.git
cd level.js
npm install
npm test
open localhost:9966

Then look in your browser console

license

BSD

Changelog

[2.1.2] - 2014-04-05

Added

• Add link to @brycebaril's presentation to README (@maxogden)

Changed

• Update browser configuration for Testling (@maxogden)