WebRTC Chord Platform

A p2p platform based on Chord protocol using WebRTC data channels.

In this implementation, the server is used to signal the first connection of a peer to another peer in the network, the next connections between peers are signalled in a distributed manner using routing adhoc between the already connected peers. The server itself also acts a peer in the network (it's the first peer of the network), both server and clients use the same codebase.

Build

$ npm install
$ webpack

Setup

Server

Configuration file parameters:

• debug: activate/deactivate verbose logging
• url: address in which the server will be running
• m: the size of the network, where size = 2^m
• sha1: use SHA-1 identifiers or integers

Example:

{
    "debug": false,
    "url": "http://localhost:8080",
    "m": 3,
    "sha1": false
}

To start the server:

node server.js config-file.json

config-file.json is optional, if not defined then default configurations are used (from file config-default.json).

Client

Include webrtc-chord-platform.js:

<script type="text/javascript" src="path/to/webrtc-chord-platform.js"></script>

Create a chord instance:

var chord = new Chord(options);

options is an object with configuration parameters, example:

options = {
    url: "http://localhost:8080", //server url
    debug: false, //activate/deactivate verbose logging
    storage: sessionStorage //optional, let's you define the key-value object as long as it uses the setItem/getItem API
}

Usage

Join the p2p network

chord.join(function(id){
	//returns the id when joined successfully
});

User Events

It's possible to define custom events (syntax like socket.io)

chord.on('event_name', function(data) {
    console.log("This is my callback event_name");
});

Communicate with a specific peer

It's possible to send data directly to a peer as long as a direct connection exist between the two

List direct connections

chord.getConnections();

Get a direct connection to a specific peer

chord.connectTo(id, function(event) {
	//event
    //-yourself - trying to connect to yourself
    //-connected - is connected
    //-not_connected - is not connected
});

Emit custom event to specific peer

chord.emit('event_name', id_other_peer, data);

Broadcast

Broadcast messages to all network peers:

chord.broadcast(“MESSAGE”);

Register broadcast callback:

chord.on('broadcast', function(data) {
        console.log("This is my callback broadcast");
        console.log(data);
});

Leave the p2p network

chord.leave();

Store value

Stores a value in the network

chord.storeValue(myValue);

Get value

Get a value from the network by its hash

chord.getValue(hash, function(value) {
        console.log("This is my callback");
});

Client example

The client-example/client.html file is an example of a possible client.

Copyright and License

Copyright 2015 Bruno Faria, Instituto de Telecomunicações, Wavecom

Licensed under the GPLv3

Acknowledgements