@dashevo/dapi-db

DapiDB

A peer-to-peer database for the decentralized web

DapiDB is a serverless, distributed, peer-to-peer database. DapiDB uses IPFS as its data storage and IPFS Pubsub to automatically sync databases with peers. It's an eventually consistent database that uses CRDTs for conflict-free database merges making DapiDB an excellent choice for decentralized apps (dApps), blockchain applications and offline-first web applications.

Data in DapiDB can be stored in a

• Key-Value Store
• Log Database (append-only log)
• Feed (same as log database but entries can be removed)
• Document Store (store indexed JSON documents)
• Counters

This is the Javascript implementation and it works both in Node.js and Browsers.

To get started, try the DapiDB CLI, read the Getting Started Guide or check Live demo 1, Live demo 2 or P2P TodoMVC app!

Table of Contents

• Usage
• API
• Examples
• Development
• Background
• Contributing
• License

Usage

Read the GETTING STARTED guide for a more in-depth tutorial and to understand how DapiDB works.

DapiDB currently supports Linux and OS X, Windows is not supported yet.

CLI

For the CLI tool to manage orbit-db database, see DapiDB CLI.

It can be installed from Npm with:

npm install orbit-db-cli -g

As a library

Install dependencies:

npm install orbit-db ipfs

Use it as a module:

const IPFS = require('ipfs')
const DapiDB = require('orbit-db')

// DapiDB uses Pubsub which is an experimental feature
// and need to be turned on manually.
// Note that these options need to be passed to IPFS in 
// all examples even if not specfied so.
const ipfsOptions = {
  EXPERIMENTAL: {
    pubsub: true
  },
}

// Create IPFS instance
const ipfs = new IPFS(ipfsOptions)

ipfs.on('error', (e) => console.error(e))
ipfs.on('ready', async () => {
  // Create a database
  const dapidb = new DapiDB(ipfs)
  const db = await dapidb.log('database name')
  // Add an entry to the database
  const hash = await db.add('hello world')
  // Get last 5 entries
  const latest = db.iterator({ limit: 5 }).collect()
  console.log(JSON.stringify(latest, null, 2))
})

For more details, see examples for kvstore, eventlog, feed, docstore and counter.

The minimum required version of Node.js is now 8.0.0. To use with older versions of Node.js, we provide an ES5-compatible build through the npm package, located in dist/es5/ when installed through npm.

API

See API documentation for the full documentation.

• Getting Started
• DapiDB
  • keyvalue
  • log
  • feed
  • docstore
  • counter
  • common

Examples

Install dependencies

git clone https://github.com/dashevo/dapi-db.git
cd orbit-db
npm install

You'll also need babel and webpack, if you don't have them installed already:

npm install --global babel-cli
npm install --global webpack

Some dependencies depend on native addon modules, so you'll also need to meet node-gyp's installation prerequisites. Therefore, Linux users may need to

make clean && make

to redo the local package-lock.json with working native dependencies.

Browser example

In macOS:

npm run build
npm run examples:browser-macos

In Linux:

npm run build
npm run examples:browser-linux

Check the code in examples/browser/browser.html and try the live example.

Node.js example

npm run examples:node

Eventlog

See the code in examples/eventlog.js and run it with:

node examples/eventlog.js

More examples at examples.

Custom Store Types

You can add custom store types to DapiDB:

// define custom store type
class CustomStore extends DocumentStore {
  constructor (ipfs, id, dbname, options) {
    super(ipfs, id, dbname, options)
    this._type = CustomStore.type
  }

  static get type () {
    return 'custom'
  }
}

// add custom type to dapidb
DapiDB.addDatabaseType(CustomStore.type, CustomStore)

// instantiate custom store
let dapidb = new DapiDB(ipfs, dbPath)
let store = dapidb.create(name, CustomStore.type)

Development

Run Tests

npm test

Build

npm run build

Benchmark

node benchmarks/benchmark-add.js

See benchmarks/ for more benchmarks.

Logging

To enable DapiDB's logging output, set a global ENV variable called LOG to debug,warn or error:

LOG=debug node <file>

Background

Uses the following modules:

• ipfs-log
• crdts
• dapi-db-cache
• dapi-db-store
• dapi-db-eventstore
• dapi-db-feedstore
• dapi-db-kvstore
• dapi-db-docstore
• dapi-db-counterstore
• orbit-db-pubsub
• orbit-db-keystore
• ipfs
• ipfs-pubub-room

To understand a little bit about the architecture, check out a visualization of the data flow at https://github.com/haadcode/proto2 or a live demo: http://celebdil.benet.ai:8080/ipfs/Qmezm7g8mBpWyuPk6D84CNcfLKJwU6mpXuEN5GJZNkX3XK/.

License

MIT ©️ 2017 Haadcode