product-scanner

MDNS network scanner for holusion products

Example usage : see example.js.

Import

import ProductScanner from "@holusion/product-scanner";
const s = new ProductScanner(); //Defaults are usually good

API

Events

error

forwards errors from multicast-dns.

ready

emits a ready event once multicast-dns started successfully It is necessary to wait for it before calling ProductScanner.refresh().

change

emitted each time a new node is detected or some node is updated.

Does not perform deduplication so it might get called a lot on noisy networks.

remove

Emitted with the node's host property if a node is removed, either due to timeout or graceful shutdown

Methods

refresh(ids :string, timeout:number=500)

force-refresh a list of hosts within a set time.

Everything that did not respond on time will be removed through the emission of a "remove" event.

Resolves once the timeout expires or all nodes answered.

close()

closes the scanner and the underlying multicast-dns socket if using the default one.

Improvements

• currently no difference is made between services ttl (long) and addresses ttl (short). a record-dependant refresh cycle could be established
• refresh could be improved. It currently does a broadcast instead of sending requests only to target nodes
• some "network health" statistics could be gathered to use a network-dependant value for refresh's timeout.