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use std::time::Duration;
use clap::Parser;
use hiroz::{
Builder, Result,
context::{ZContext, ZContextBuilder},
};
use hiroz_msgs::std_msgs::String as RosString;
/// Subscriber function that continuously receives messages from a topic
async fn run_subscriber(ctx: ZContext, topic: String) -> Result<()> {
// Create a ROS 2 node - the fundamental unit of computation
// Nodes are logical groupings of publishers, subscribers, services, etc.
let node = ctx.create_node("listener").build()?;
// Create a subscriber for the specified topic
// The type parameter RosString determines what message type we'll receive
let zsub = node.create_sub::<RosString>(&topic).build()?;
// Continuously receive messages asynchronously
// This loop will block waiting for messages on the topic
while let Ok(msg) = zsub.async_recv().await {
println!("Hearing:>> {}", msg.data);
}
Ok(())
}
/// Publisher function that continuously publishes messages to a topic
async fn run_publisher(
ctx: ZContext,
topic: String,
period: Duration,
payload: String,
) -> Result<()> {
// Create a ROS 2 node for publishing
let node = ctx
.create_node("talker")
.with_type_description_service()
.build()?;
// Create a publisher for the specified topic
// The type parameter RosString determines what message type we'll send
let zpub = node.create_pub::<RosString>(&topic).build()?;
let mut count = 0;
loop {
// Create a new message with incrementing counter
let str = RosString {
data: format!("{payload} - #{count}"),
};
println!("Telling:>> {}", str.data);
// Publish the message asynchronously to all subscribers on this topic
zpub.async_publish(&str).await?;
// Wait for the specified period before publishing again
let _ = tokio::time::sleep(period).await;
count += 1;
}
}
// The #[tokio::main] attribute sets up the async runtime
// hiroz requires an async runtime (Tokio is the most common choice)
#[tokio::main]
async fn main() -> Result<()> {
let args = Args::parse();
let format = hiroz_protocol::KeyExprFormat::RmwZenoh;
// Create a ZContext - the entry point for hiroz applications
// ZContext manages the connection to the Zenoh network and coordinates
// communication between nodes. It can be configured with different modes:
// - "peer" mode: nodes discover each other via multicast scouting
// - "client" mode: nodes connect to a Zenoh router
let ctx = if let Some(e) = args.endpoint {
ZContextBuilder::default()
.with_mode(args.mode)
.with_connect_endpoints([e])
.keyexpr_format(format)
.build()?
} else {
ZContextBuilder::default()
.with_mode(args.mode)
.keyexpr_format(format)
.build()?
};
let period = std::time::Duration::from_secs_f64(args.period);
zenoh::init_log_from_env_or("error");
// Run as either a publisher (talker) or subscriber (listener)
// Both share the same ZContext but perform different roles
match args.role.as_str() {
"listener" => run_subscriber(ctx, args.topic).await?,
"talker" => run_publisher(ctx, args.topic, period, args.data).await?,
role => println!(
"Please use \"talker\" or \"listener\" as role, {} is not supported.",
role
),
}
Ok(())
}
#[derive(Debug, Parser)]
struct Args {
#[arg(short, long, default_value = "Hello hiroz")]
data: String,
#[arg(short, long, default_value = "/chatter")]
topic: String,
#[arg(short, long, default_value = "1.0")]
period: f64,
#[arg(short, long, default_value = "listener")]
role: String,
#[arg(short, long, default_value = "peer")]
mode: String,
#[arg(short, long)]
endpoint: Option<String>,
}