rocket.chat.mqtt/node_modules/aedes/lib/handlers/pubrel.js

It's a MQTT Server, using redis to scale horizontally.

'use strict'

var write = require('../write')

function ClientPacketStatus (client, packet) {
  this.client = client
  this.packet = packet
}

function PubComp (packet) {
  this.cmd = 'pubcomp'
  this.messageId = packet.messageId
}

var pubrelActions = [
  pubrelGet,
  pubrelPublish,
  pubrelWrite,
  pubrelDel
]
function handlePubrel (client, packet, done) {
  client.broker._series(
    new ClientPacketStatus(client, packet),
    pubrelActions, {}, done)
}

function pubrelGet (arg, done) {
  var persistence = this.client.broker.persistence
  persistence.incomingGetPacket(this.client, this.packet, reply)

  function reply (err, packet) {
    arg.packet = packet
    done(err)
  }
}

function pubrelPublish (arg, done) {
  this.client.broker.publish(arg.packet, this.client, done)
}

function pubrelWrite (arg, done) {
  write(this.client, new PubComp(arg.packet), done)
}

function pubrelDel (arg, done) {
  var persistence = this.client.broker.persistence
  persistence.incomingDelPacket(this.client, arg.packet, done)
}

module.exports = handlePubrel