src/network/communication/unicast/unicast.js

'use strict'

const AbstractUnicast = require('./../abstract/abstract-unicast.js')
const UnicastDefinition = require('unicast-definition')

/**
 * Unicast represent the base implementation of an unicast protocol for the foglet library.
 * @extends AbstractUnicast
 * @author Arnaud Grall (Folkvir)
 */
class Unicast extends AbstractUnicast {
  /**
   * Constructor
   * @param  {AbstractNetwork} source - The source RPS/overlay
   * @param  {string} protocol - The name of the unicast protocol
   */
  constructor (source, protocol) {
    super(source, protocol)
    this._unicast = new UnicastDefinition(this._source.rps, {pid: this._protocol})
    this._unicast.on(this._protocol, (id, message) => {
      this._receive(id, message)
    })
  }

  /**
   * Send a message to a peer using its ID.
   * This peer must be a neighbour.
   * @param  {string}  id  - The id to send the message
   * @param  {*} message - The message to send
   * @return {Promise} A Promise fulfilled when the message is sent
   */
  send (id, message) {
    return this._unicast.emit(this._protocol, id, this._source.outviewId, message)
  }

  /**
   * Send a message to multiple peers
   * @param  {string[]} ids - Set of peer IDs
   * @param  {Object} message - Message to send
   * @return {Promise} A Promise fulfilled when all message have been sent
   */
  sendMultiple (ids = [], message) {
    return ids.reduce((prev, peerID) => {
      return prev.then(() => this.send(peerID, message))
    }, Promise.resolve())
  }

  /**
   * Handler executed when a message is recevied
   * @param  {string} id  - Message issuer's ID
   * @param  {*} message - The message received
   * @return {void}
   */
  _receive (id, message) {
    this.emit('receive', id, message)
  }
}

module.exports = Unicast