@mangar2/broker NPM

Abstract

The ( mqtt ) broker is a central service receiving and distributing messages to all subscribed receipiens . Use the "brokerservice" module to start the broker .


File	broker.js
Abstract	The ( mqtt ) broker is a central service receiving and distributing messages to all subscribed receipiens . Use the "brokerservice" module to start the broker .
Author	Volker Böhm
Copyright	Copyright ( c ) 2020 Volker Böhm
License	This software is licensed under the GNU LESSER GENERAL PUBLIC LICENSE Version 3 . It is furnished "as is" , without any support , and with no warranty , express or implied , as to its usefulness for any purpose .

Class Broker

new Broker(configuration)

Creates a new broker

Example

const configuration = {
     port: 10000,
     persistInterval: 0,
     connections: {
          directory: '.',
          fileName: 'broker',
          log: [
              {
                  module: 'received',
                  topic: '#'
              }
          ]
      }
  }
const broker = new Broker(configuration)
broker.run()

Broker Parameters

Name	Type	Description
`configuration`	`Object`	configuration for the broker

configuration properties

Name	Type	Attribute	Default	Description
`port`	`number, string`			port number the broker will listen on
`persistInterval`	`number`	optional	60 * 1000	Intervall between persisting internal state to file in milliseconds . Persistance is not called if this value is 0
`connections`	`Object`			connection settings for the broker

connections properties

Name	Type	Attribute	Default	Description
`fileName`	`string`			filename for persistence
`directory`	`string`			directory ( file path ) for persistence
`replyTimeoutInMilliseconds`	`number`			timeout to wait for an answer of a http call
`inFlightWindow`	`number`	optional	1	amount of qos 1 and qos 2 messages send for the same topic at the same time
`pubrelTimeoutInMilliseconds`	`number`	optional	one day	temeout to wait for a corresponding pubrel message
`maxRetryCount`	`number`			amount of resend of messages before forcing a disconnect
`maxQueuSize`	`number`			maximal amount of entries in a message queue
`log`	`Object`			log settings

Broker Methods

close

async close ()

Closes the broker , stops listening

connect

connect (host, port)

Connects to a friendly broker and subscribs for all messages

connect Parameters

Name	Type	Description
`host`	`string`	name of the host ( or his ip )
`port`	`number`	port number to connect to

on

on (event, callback)

Sets a callback .

on Parameters

Name	Type	Description
`event`	`string`	callback name ( supports 'send' and 'publish' ) 'send' is called to send data . This function is provided by the broker but could be overwritten 'publish' is called on receiving data . This function if provided by the broker but could be overwritten
`callback`	`function`