https://github.com/dat-ecosystem-archive/discovery-channel

Search for a key across multiple discovery networks and find peers who answer. [ DEPRECATED - see https://github.com/hyperswarm/dht for similar functionality. More info on active projects and modules at https://dat-ecosystem.org/ ]
https://github.com/dat-ecosystem-archive/discovery-channel

Last synced: 9 days ago
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Search for a key across multiple discovery networks and find peers who answer. [ DEPRECATED - see https://github.com/hyperswarm/dht for similar functionality. More info on active projects and modules at https://dat-ecosystem.org/ ]

• Host: GitHub
• URL: https://github.com/dat-ecosystem-archive/discovery-channel
• Owner: dat-ecosystem-archive
• Archived: true
• Created: 2015-11-23T00:09:53.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2022-01-06T01:43:21.000Z (almost 3 years ago)
• Last Synced: 2024-05-01T19:29:18.053Z (6 months ago)
• Language: JavaScript
• Homepage:
• Size: 50.8 KB
• Stars: 299
• Watchers: 9
• Forks: 34
• Open Issues: 12
• Metadata Files:
  • Readme: readme.md

Awesome Lists containing this project

• awesome-peer-to-peer - discovery-channel

README

        
[![deprecated](http://badges.github.io/stability-badges/dist/deprecated.svg)](https://github.com/hyperswarm/dht) See [hyperswarm/dht](https://github.com/hyperswarm/dht) for similar functionality. 

More info on active projects and modules at [dat-ecosystem.org](https://dat-ecosystem.org/)  

---

# discovery-channel

Search for a key across multiple discovery networks and find peers who answer.

Currently searches across and advertises on [the Bittorrent DHT](https://en.wikipedia.org/wiki/Mainline_DHT), centralized DNS servers and [Multicast DNS](https://en.wikipedia.org/wiki/Multicast_DNS) simultaneously.

Uses the [bittorrent-dht](https://github.com/feross/bittorrent-dht) and [dns-discovery](https://github.com/mafintosh/dns-discovery) modules.

Also check out [discovery-swarm](https://github.com/mafintosh/discovery-swarm) which adds connection management on top of this module.

[![travis][travis-image]][travis-url]

[travis-image]: https://img.shields.io/travis/maxogden/discovery-channel.svg?style=flat

[travis-url]: https://travis-ci.org/maxogden/discovery-channel

## Usage

### `var DC = require('discovery-channel')`

Returns a constructor

### `var channel = DC()`

Returns a new instance. `opts` is optional and can have the following properties:

- `dns` - default `undefined`, if `false` will disable `dns` discovery, any other value type will be passed to the `dns-discovery` constructor

- `dht` - default `undefined`, if `false` will disable `dht` discovery, any other value type will be passed to the `bittorrent-dht` constructor

- `hash` - default `sha1`. 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

``` js

{

  id: ,

  port: 

}

```

### `channel.on('peer', id, peer, type)`

Emitted when a peer answers your query.

- `id` is the id (as a buffer) this peer was discovered for

- `peer` 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