discovery-swarm

A network swarm that uses discovery-channel to find and connect to peers.

This module implements peer connection state and builds on discovery-channel which implements peer discovery. This uses TCP sockets by default and has experimental support for UTP.

npm install discovery-swarm

Usage

var swarm = require('discovery-swarm')

var sw = swarm()

sw.listen(1000)
sw.join('ubuntu-14.04') // can be any id/name/hash

sw.on('connection', function (connection) {
  console.log('found + connected to peer')
})

API

var sw = swarm(opts)

Create a new swarm. Options include:

{
  id: crypto.randomBytes(32), // peer-id for user
  stream: stream, // stream to replicate across peers
  connect: fn, // connect local and remote streams yourself
  utp: true, // use utp for discovery
  tcp: true, // use tcp for discovery
  maxConnections: 0, // max number of connections.
  whitelist: [], // array of ip addresses to restrict connections to
  keepExistingConnections: false  // by default, prefer tcp by dropping old utp connections
}

For full list of opts take a look at discovery-channel

sw.join(key, [opts], [cb])

Join a channel specified by key (usually a name, hash or id, must be a Buffer or a string). After joining will immediately search for peers advertising this key, and re-announce on a timer.

If you pass opts.announce as a falsy value you don't announce your port (e.g. you will be in discover-only mode)

If you specify cb, it will be called when the first round of discovery has completed. But only on the first round.

sw.leave(key)

Leave the channel specified key

sw.connecting

Number of peers we are trying to connect to

sw.queued

Number of peers discovered but not connected to yet

sw.connected

Number of peers connected to

sw.on('peer', function(peer) { ... })

Emitted when a peer has been discovered. Peer is an object that contains info about the peer.

{
  channel: Buffer('...'), // the channel this connection was initiated on.
  host: '127.0.0.1', // the remote address of the peer.
  port: 8080, // the remote port of the peer.
  id: '192.168.0.5:64374@74657374', // the remote peer's peer-id.
  retries: 0 // the number of times tried to connect to this peer.
}

sw.on('peer-banned', function(peerAddress, details) { ... })

Emitted when a peer has been banned as a connection candidate. peerAddress is an object that contains info about the peer. Details is an object that describes the rejection.

{
  reason: 'detected-self' // may be 'application' (removePeer() was called) or 'detected-self'
}

sw.on('peer-rejected', function(peerAddress, details) { ... })

Emitted when a peer has been rejected as a connection candidate. peerAddress is an object that contains info about the peer. Details is an object that describes the rejection

{
  reason: 'duplicate' // may be 'duplicate', 'banned', or 'whitelist'
}

sw.on('drop', function(peer) { ... })

Emitted when a peer has been dropped from tracking, typically because it failed too many times to connect. Peer is an object that contains info about the peer.

sw.on('connecting', function(peer) { ... })

Emitted when a connection is being attempted. Peer is an object that contains info about the peer.

sw.on('connect-failed', function(peer, details) { ... })

Emitted when a connection attempt fails. Peer is an object that contains info about the peer. Details is an object that describes the failure

{
  timedout: true // was the failure a timeout?
}

sw.on('handshaking', function(connection, info) { ... })

Emitted when you've connected to a peer and are now initializing the connection's session. Info is an object that contains info about the connection.

{
  type: 'tcp', // the type, tcp or utp.
  initiator: true, // whether we initiated the connection or someone else did.
  channel: Buffer('...'), // the channel this connection was initiated on. only set if initiator === true.
  host: '127.0.0.1', // the remote address of the peer.
  port: 8080, // the remote port of the peer.
  id: Buffer('...') // the remote peer's peer-id.
}

sw.on('handshake-timeout', function(connection, info) { ... })

Emitted when the handshake fails to complete in a timely fashion. Info is an object that contains info about the connection.

sw.on('connection', function(connection, info) { ... })

Emitted when you have fully connected to another peer. Info is an object that contains info about the connection.

sw.on('connection-closed', function(connection, info) { ... })

Emitted when you've disconnected from a peer. Info is an object that contains info about the connection.

sw.on('redundant-connection', function(connection, info) { ... })

Emitted when multiple connections are detected with a peer, and so one is going to be dropped (the connection given). Info is an object that contains info about the connection.

sw.listen(port)

Listen on a specific port. Should be called before join

License

MIT