k-rpc-socket

Low level implementation of the k-rpc network layer that the BitTorrent DHT uses.
Mostly extracted from the bittorrent-dht module on npm into its own repo.

``
npm install k-rpc-socket
`

![build status](http://travis-ci.org/mafintosh/k-rpc-socket)

Usage

` js
var rpc = require('k-rpc-socket')

var socket = rpc()

socket.on('query', function (query, peer) {
socket.response(peer, query, {echo: query.a})
})

socket.bind(10000, function () {
var anotherSocket = rpc()
anotherSocket.query({host: '127.0.0.1', port: 10000}, {q: 'echo', a: {hello: 'world'}}, function (err, response) {
console.log(response.r) // prints {echo: {hello: Buffer('world')}}
})
})
`

API

#### var socket = rpc([options])

Create a new k-rpc-socket. Options include:

` js
{
timeout: queryTimeout, // defaults to 2s
socket: optionalUdpSocket,
isIP: optionalBooleanFunction
}
`

#### socket.send(peer, message, [callback])

Send a raw message. The callback is called when the message has been flushed from the socket.

#### var id = socket.query(peer, query, [callback])

Send a query message. The callback is called with (err, response, peer, request).
You should set the method name you are trying to call as {q: 'method_name'} and query data as {a: someQueryData}.

The query method returns a query id. You can use this id to cancel the query using the .cancel method.

#### socket.cancel(id)

Cancel a query. Will call the corresponding query's callback with an error indicating that it was cancelled.

#### socket.response(peer, query, response, [callback])

Send a response to a query. The callback is called when the message has been flushed from the socket.

#### socket.error(peer, query, error, [callback])

Send an error reploy to a query. The callback is called when the message has been flushed from the socket.

#### socket.inflight

Integer representing the number of concurrent queries that are currently pending.

#### socket.destroy()

Destroys and unbinds the socket

#### socket.bind([port], [address], [callback])

Call this to bind to a specific port. If port is not specified or is 0, the operating system
will attempt to bind to a random port. If address is not specified, the operating system will
attempt to listen on all addresses.

If you don't call this a random free port will be chosen.

#### socket.on('query', query, peer)

When a query is received a query event is emitted with the query data and a peer object representing the querying peer.

#### socket.on('warning', error)

Emitted when a non fatal error has occured. It is safe to ignore this.

#### socket.on('error', error)`

Emitted when a fatal error has occured.

License

MIT