Pocdb NPM | npm.io

pocdb

Lightweight eventually consistent key/value database.

LIB

Installation

$ npm install pocdb

Usage

Start pocdb engine

const pocdb = require("pocdb")
const configuration = { path: "./data", address: "127.0.0.1, port: 8000 }
pocdb.start(configuration)

Query pocdb engine

pocdb.put("key", "value")
pocdb.get("key")
pocdb.destroy("key")

Create db backup

A backup is named after the data path, suffixed with a current timestamp generated during the call.

pocdb.backup()

Stop pocdb engine

pocdb.stop()

CLI

Installation

$ npm install -g pocdb

Usage

Start pocdb engine and http server

pocdb --path=./data.json --address=127.0.0.1 --port=2222

Configuration

Configuration of pocdb is made up of the following properties :

path

The path of the pocdb persisted data.

address

The listening address of pocdb http server ( default 127.0.0.1 )

port

The listening port of pocdb http server ( default 2222 )

HTTP

At pocdb start an http server is also started at the configured address and port to provide CRUD access to pocdb data.

Data explorer access

Data explorer web interface is available under reserved path "/_explorer"

The web interface is a fork of project "react-json-editor". Original project page at https://github.com/sujinleeme/react-json-editor

Database access

Database HTTP access is available under reserved path "/_database"

Path convention

For any database access HTTP request, the request subpath will be translated into a specific db key, starting after "/_database/" root path. Any "/" will be converted as an internal key separator in the data tree structure. For example an HTTP request ( GET / PUT / DELETE ) sent at "/_database/users/1" path will be internally processed as an equivalent CRUD operation on "users.1" key in the database.

Note : Root path "/_database" PUT and DELETE requests won't update the database whereas GET request will fetch the whole database.

Create / Update

Put a value at a specific key

Method

PUT / POST

Body

{ "value": <ANY_VALUE> }

Response

{ "statusCode": 200, "message": "key updated" }

Read

Read a value at a specific key

Method

GET

Response

{ "statusCode": 200, "value": <ANY_VALUE> }

Delete

Delete a value at a specific key

Method

DELETE

Response

{ "statusCode": 200, "message": "key destroyed" }

Eventual consistency

Data synchronisation is supported accross several instances of pocdb referencing the same persisted data file. A .pocdb log file is saved under the same location than the persisted data file. Real-time updates to .pocdb log file are performed to achieve synchronization accross any number of pocdb instances referencing the data file. Synchronization time is of 1 second, meaning eventual consistency for pocdb is reached after 1 second at most.