uci-interrupt/src/interrupt.js

import Base from '@uci/base'
import DeadJim from 'death'
import { Gpio } from 'onoff'

import logger from '@uci-utils/logger'
let log = logger({package:'@uci/interrupt', file:'/src/interrupt.js'})
// a pin makes a socket (server/listner) for each pin to which a consumer can be connected
//  if opts .port/.path/.topic/.wport are base number/name to which pin number is added/appended (default being 9000,9100,'interrupt')
// for specific port number pass itrt.port,itrn.path,itrm.topic,itrw.port which override it if present
// conPacket is for connecting consumers.  This will send this conPacket command on connect, which may needed to initilize something on related hardware
class Interrupt extends Base {
  constructor(pin, opts = {}) {
    if (typeof pin !=='number') pin = parseInt(pin)  // make sure pin is a number!
    opts.conPacket = (opts.resetCmd && !opts.conPacket) ? { cmd: opts.resetCmd, pin: pin } :  opts.conPacket   // will use either option
    log.debug({conPacket: opts.conPacket, msg:'connection packet for consumers'})
    if (opts.path || opts.itrn) {
      opts.itrn = opts.itrn || {}
      if (opts.path && typeof opts.path !=='boolean') opts.path = opts.path + ':' + pin
      if (typeof opts.path ==='boolean') opts.path = ''
      opts.itrn.path =  opts.itrn.path || opts.path || 'interrupt:' + pin
      opts.itrn.conPacket = opts.conPacket
      opts.sockets = (opts.sockets ? opts.sockets + ',' : '') + 'itrn#s>n'
    }
    if (opts.topic || opts.itrm) {
      opts.itrm = opts.itrm || {}
      opts.itrm.topics = opts.itrm.topic || opts.topic +'/'+ pin || 'interrupt/' + pin
      opts.sockets = (opts.sockets ? opts.sockets + ',' : '') + 'itrm#s>m'
    }

    if (opts.itrw || opts.wport || opts.wport===0 ) {
      opts.itrw = opts.itrw || {}
      if (opts.wport) opts.wport = opts.wport + +pin
      opts.itrw.port = opts.itrw.port || opts.wport || 9100 + +pin
      opts.sockets = (opts.sockets ? opts.sockets + ',' : '') + 'itrw#s>w'
    }
    // default is a tcp socket server at 9000+pin
    if (opts.itrt || opts.port || opts.port===0 || !opts.sockets ) {
      opts.itrt = opts.itrt || {}
      if (opts.port) opts.port = opts.port + +pin
      opts.itrt.port = opts.itrt.port || opts.port || 9000 + +pin
      opts.itrt.conPacket = opts.conPacket
      opts.sockets = (opts.sockets ? opts.sockets + ',' : '') + 'itrt#s>t'
    }
    super(opts)
    this.id = (opts.id || 'interrupt') + ':' + pin
    log.info({ pins: pin, opts: opts }, 'created interrupt with these opts')
    this.pin_num = pin
    this.mock = opts.mock || process.env.MOCK
    this.wait = opts.wait || 0 // debounce is off by default
    // https://github.com/fivdi/onoff#gpiogpio-direction--edge--options
    this.edge = opts.edge || 'rising'  // falling,both,none=no interrupt
    // this.pull = opts.pull || 'low'  // 'high'
    this.pin = {}
    this.hook = opts.hook
    this.packet = opts.packet || {}
    this.packet.id = this.id
    this.packet.pin = this.pin_num
    this.packet.cmd = this.packet.cmd || opts.pushCmd || 'interrupt'
    this.packet.count = 0
    this._hookFunc = defaultHook
    this.s = { fire:this.fire.bind(this)} // make fire available via consumer packet send
  } // end constructor

  async init() {
    await super.init()

    DeadJim( (signal,err) => {
      log.warn({signal:signal, error:err, msg:'Interrupt was killed'})
      this.pin.unwatchAll()
      this.pin.unexport() // kill the kernel entry

    })

    this.pin = new Gpio(this.pin_num, 'in', this.edge, { debounceTimeout:this.wait })

    log.debug({msg:'new interrupt pin created and watching', pin:this.pin, edge:this.edge,debounce:this.wait})

    this.pin.watch( function (err,value) {
      log.debug('sbc interrupt tripped', err, value)
      this._interruptProcess(this.packet,err,value)
    }.bind(this))

  } // end init

  // manual firing for testing
  async fire(packet) {
    console.log('manually firing interrupt for pin', this.pin_num)
    await this._interruptProcess(this.packet,null,'manual')
    packet.status = 'fired'
    return packet
  }

  // use hook to do more processing
  async _interruptProcess(packet,err,value) {
    console.log('from watch listener', packet.pin, err, value)
    packet.error = err
    packet.state = value
    packet.count += 1
    packet.time = new Date().getTime()
    if (this.hook) packet = await this._hookFunc.call(this,packet)
    log.debug({ pin:this.pin, packet: packet }, 'packet pushing to all clients')
    await this.push(packet)
  }


  registerHook(func) {
    this._hookFunc = func
  }

} // end Class

export default Interrupt


//default hook
async function defaultHook(packet) {
  // return a promise or use await if anything async happens in hook
  // new Promise((resolve) => {
  console.log('==========default hook =============')
  console.log(`pin ${packet.pin} on sbc gpio bus has thrown an interrupt`)
  console.log(`pushing to all connected socket client with cmd:${packet.cmd}`)
  console.dir(packet)
  console.log('replace by a new function with .registerHook(function) to overwrite this')
  console.log('Must be async/promise returning if anything async happens in your hook')
  console.log('This hook allows you to modify/add to the packet being pushed to connected clients')
  console.log('the function will be bound to the instance for complete access')
  console.log('if you pass a hash for .hook you can use it here as this.hook')
  console.log('the hook options contains', this.hook)
  console.log('by default the instance id will be attached to the packet before this')
  return packet
  // resolve(packet)
  // })
}