Class HostMap

lib/host.js:454–655

* Represents an associative-array of Host hosts that can be iterated. * It creates an internal copy when adding or removing, making it safe to iterate using the values() * method within async operations. * @extends events.EventEmitter * @constructor

 * @constructor
 */
class HostMap extends events.EventEmitter{
  constructor() {
    super();

    this._items = new Map();
    this._values = null;

    Object.defineProperty(this, 'length', { get: () => this.values().length, enumerable: true });

    /**
     * Emitted when a host is added to the map
     * @event HostMap#add
     */
    /**
     * Emitted when a host is removed from the map
     * @event HostMap#remove
     */
  }

  /**
   * Executes a provided function once per map element.
   * @param callback
   */
  forEach(callback) {
    const items = this._items;
    for (const [ key, value ] of items) {
      callback(value, key);
    }
  }

  /**
   * Gets a {@link Host host} by key or undefined if not found.
   * @param {String} key
   * @returns {Host}
   */
  get(key) {
    return this._items.get(key);
  }

  /**
   * Returns an array of host addresses.
   * @returns {Array.<String>}
   */
  keys() {
    return Array.from(this._items.keys());
  }

  /**
   * Removes an item from the map.
   * @param {String} key The key of the host
   * @fires HostMap#remove
   */
  remove(key) {
    const value = this._items.get(key);
    if (value === undefined) {
      return;
    }