Function select

Negotiate a protocol to use from a list of protocols.

Returns

A stream for the selected protocol and the protocol that was selected from the list of protocols provided to select.

Example

import { pipe } from 'it-pipe'
import * as mss from '@libp2p/multistream-select'
import { Mplex } from '@libp2p/mplex'

const muxer = new Mplex()
const muxedStream = muxer.newStream()

// mss.select(protocol(s))
// Select from one of the passed protocols (in priority order)
// Returns selected stream and protocol
const { stream: dhtStream, protocol } = await mss.select(muxedStream, [
  // This might just be different versions of DHT, but could be different impls
  '/ipfs-dht/2.0.0', // Most of the time this will probably just be one item.
  '/ipfs-dht/1.0.0'
])

// Typically this stream will be passed back to the caller of libp2p.dialProtocol
//
// ...it might then do something like this:
// try {
//   await pipe(
//     [uint8ArrayFromString('Some DHT data')]
//     dhtStream,
//     async source => {
//       for await (const chunk of source)
//         // DHT response data
//     }
//   )
// } catch (err) {
//   // Error in stream
// }