Kademlia

A Kademlia DHT implementation in node, ready to be used as a distributed data store.

Install using npm install p2pdht

Use:

var dht = require('p2pdht')
var node = new dht.KNode({ address: 'IP address', port: portNumber });
node.connect('existing peer ip', port);
node.set('foo', 'bar');

node.get('foo', function(err, data) {
    console.log("Retrieved", data, "from DHT");
    console.log(data == 'bar');
});

API

KNode

The KNode represents a Kademlia node and handles all communication and storage. This should be the only thing you need to interact with the Kademlia overlay network.

KNode(configuration)

A KNode is created by passing it an object having address and port properties. The node will bind to port and start running.

var node = new dht.KNode({ address: '10.100.98.60', port: 12345 });

connect(address, port[, callback])

Used to introduce this Kademlia node to the overlay network. If you know the address and port of an existing Kademlia peer, you may connect to it so that this node can become part of the network. If callback is passed it is called with the result of the join. connect succeeds (err is null) when the entire Kademlia join sequence is finished.

node.connect('10.100.98.12', 42922, function(err) {
    if (err)
        process.exit();
    startHeavyLifting();
});

get(key, callback)

Gets the value associated with key from the Kademlia network. callback is a function with arguments (err, value). If the value is found, err is null, otherwise err will be an object containing information about what went wrong and value will be null.

node.get('foo', function(err, value) {
    if (err) {
        // something went wrong
        return;
    }

    // use value
});

set(key, value[, callback])

Store the key, value pair in the Kademlia network. set() is not guaranteed to succeed. callback can be used to check the result of the store. It is function (err). If the store succeeded, err is null, otherwise err describes what went wrong.

node.set('foo', 'bar', function(err) {
    if (err) {
        // might want to try again
    }
});

self

An object describing this node. self is frozen, attempts to modify it will fail (and raise an exception in strict mode).

node.self is {
    nodeID: 'f386f180b2722ab92060661152e680b88976126f',
    address: '10.100.98.60',
    port: 12345
}

Hacking

To use the test scripts, assign the IP address to bind to, to the environment variable KADEMLIA_BIND_ADDRESS.

License

See LICENSE.