discovery-channel
Search for a key across multiple discovery networks and find peers who answer.
Currently searches across and advertises on the Bittorrent DHT, centralized DNS servers and Multicast DNS simultaneously.
Uses the bittorrent-dht and dns-discovery modules.
Also check out discovery-swarm which adds connection management on top of this module.
Usage
var DC = require('discovery-channel')
Returns a constructor
var channel = DC(<opts>)
Returns a new instance. opts
is optional and can have the following properties:
dns
- defaultundefined
, iffalse
will disabledns
discovery, any other value type will be passed to thedns-discovery
constructordht
- defaultundefined
, iffalse
will disabledht
discovery, any other value type will be passed to thebittorrent-dht
constructorhash
- defaultsha1
. provide a custom hash function to hash ids before they are stored in the dht / on dns servers.
By default hashes are re-announced around every 10 min on the dht and 1 min using dns. Set dht.interval
or dns.interval
to change these.
channel.join(id, [port], [cb])
Perform a lookup across all networks for id
. id
can be a buffer or a string.
Specify port
if you want to announce that you share id
as well.
If you specify cb
, it will be called when the first round of discovery has completed. But only on the first round.
channel.leave(id, [port])
Stop looking for id
. id
can be a buffer or a string.
Specify port
to stop announcing that you share id
as well.
channel.update()
Force announce / lookup all joined hashes
var list = channel.list()
List all the channels you have joined. The returned array items look like this
id: <Buffer>port: <port you are announcing>
channel.on('peer', id, peer, type)
Emitted when a peer answers your query.
id
is the id (as a buffer) this peer was discovered forpeer
is the peer that was discovered{port: port, host: host}
type
is the network type (one of['dht', 'dns']
)
channel.destroy(cb)
Stops all lookups and advertisements and call cb
when done.
channel.on('close')
Emitted when the channel is destroyed