Hands-On Microservices with Rust

Actors

We will add an actor to resend messages to other actors. We need some basic types from the actix crate, along with a HashSet to keep addresses of actors. Import the NewComment struct, which we will clone and resend:

use actix::{Actor, Context, Handler, Message, Recipient};use std::collections::HashSet;use super::NewComment;

Add a RepeaterActor struct with a listeners field of the HashSet type that contains Recipient instances:

pub struct RepeaterActor {    listeners: HashSet<Recipient<RepeaterUpdate>>,}

You are familiar with the Addr type, but we haven't used Recipient before. Actually, you can convert any Addr instance into a Recipient using the recipient method call. The Recipient type is an address that supports only one type of