lib/entries/epv.js

'use strict'

/**
 * Entry composing the partial view of a peer.
 */
class EPV {
  /**
     * @param {string} peerId The identifier of the neighbor.
     * @param {object} [descriptor = {}] The descriptor of this neighbor.
     */
  constructor (peerId, descriptor = {}) {
    this.peer = peerId
    this.ages = [0]
    this.descriptor = descriptor
  }

  /**
     * Update the descriptor of the entry
     * @param {object} descriptor The new descriptor assigned to this neigbhor.
     */
  update (descriptor) {
    this.descriptor = descriptor
  }

  /**
     * Increment the ages
     */
  increment () {
    this.ages = this.ages.map((age) => age + 1)
  }

  /**
     * Add a new 'instance' of this neigbhor, i.e., add a new age entry.
     */
  add () {
    this.ages.unshift(0)
  }

  /**
     * Remove the oldest entry of this neighbor.
     * @returns {boolean} True if the entry has no age anymore, false otherwise.
     */
  removeOldest () {
    this.ages.pop()
    return this.ages.length === 0
  }

  /**
     * Remove the youngest entry of this neigbhor.
     * @returns {boolean} True if the entry has no age anymore, false otherwise.
     */
  removeYoungest () {
    this.ages.shift()
    return this.ages.length === 0
  }

  /**
     * Get the oldest age of this neighbor.
     * @returns {number} The oldest age.
     */
  get oldest () {
    return this.ages[this.ages.length - 1]
  }

  /**
     * Get the number of occurrences of this neighbor.
     */
  get count () {
    return this.ages.length
  }
}

module.exports = EPV