evansofts-memdb

MEMDB ika (meowDB)

A simple, fast and pure Javascript key-value in memory database for Node JS.

Introduction

This lightweight engine can be used in place of things like LevelDB, Redis while keeping things light and very simple. Internaly, memdb uses json as storage format with an opt-in support for encryption. In order to achieve performance, memdb keeps things in a staging area for fast access. No worries, all the booking is handled for you :). We are developers too, thus we hate keeping tract of things.

Synopsis

  const MemDB = require('memdb')
  const db = new MemDB('_starwars', {encryptionKey: 'secret'}) 
 
  db.put('skywalker', {
      force: 'light',
      name: 'Luke Skywalker'
  }).then((status) => {
    console.log(status) // => true
  })
  
  db.get('skywalker').then((rsp) => {
    console.log(rps) // => [Object skywalker...]
  })

Installation

  $ npm install evansofts-memdb

API

MemDB's API is pretty simple and straigth forward. Some api methods return a promise.

• version(): Get MemDB current version
• revision(): Get the current database revision
• options(): Get the database instance options
• put(keychain, value, loose): Save data in the database
• get(keychain, defaultValue): Get data from the database
• all(): Get all data fron the database
• delete(keychain): Delete data from the database

NB: What the heck is keychain ? keychain is a concatenation of multiple object keys to obtain a path for accessing an object property in a deep level. This is a convenient way of puting/getting deeply nested object properties. The following keychain server.dev.host means accessing the host property form dev object which in turn is available in the server object as a property.

Creating or Opening a database

  /*
    By default, the databse is not encrypted and the stagging 
    operation size limit is 600 operations; of course you can move it up or down
  */
  const db = new MemDB('db_file_path', {
      stagingSize: 600, // maximum staging operation size before flushing the data 
      encryptionKey: null // optional if you need to encypt your data
  })

Saving data

put(keychain, value, loose)

Parameters	Description
keychain	Path where the data should be stored
value	The value to be stored
loose	Will create internal object of the chain if non existant, default to false

  db.put('server.dev.host', 'https://dev.alex.com', true).then((status) => {
    console.log(status) // => true
  })

Retrieving data

get(keychain, defaultValue)

Parameters	Description
keychain	Path where the data should be retrieved
defaultValue	The default value to be returned if not found

  db.get('server.dev.host', 'https://dev.alex.com').then((rsp) => {
    console.log(rsp) // => https://dev.alex.com
  })

all()

  db.all().then((rsp) => {
    console.log(rsp) // => whole database document
  })

Deleting data

delete(keychain)

Parameters	Description
keychain	Path where the data should be deleted

  db.delete('server.dev.host').then((rsp) => {
    console.log(rsp) // => true
  })

Testing

After cloning the repo and installing all dependencies (using npm install) you can run all tests using mocha:

$ npm test