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
--------

`` js
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
------------

` bash
$ 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.



$3



` js
/*
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
})
`

$3

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 |

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

$3

get(keychain, defaultValue)

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

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

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

$3

delete(keychain)

| Parameters | Description |
|-------------|-------------|
| keychain | Path where the data should be deleted |

` js
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
``