Renamed to krossbar

lib.rs:

RPC library used by Karo platform for communication.

The library:

• Receives tokio::net::UnixStream and returns RPC handle;
• Allows making calls, subscribing to an endpoint, and sending tokio::net::UnixStream using RPC connection;
• Supports replacing the stream after reconnection, resubscribing to the active subscriptions, and keeping all client handles valid;
• Supports message exchange monitoring via [Monitor]

Use rpc::Rpc::poll method to poll the stream. This includes waiting for a call or subscriptions response.

Examples

RPC calls:

use futures::{select, FutureExt};
use tokio::net::UnixStream;

use karo_common_rpc::rpc::Rpc;

async fn call() {
let stream = UnixStream::connect("/tmp/hub.sock").await.unwrap();
let mut rpc = Rpc::new(stream);

let call = rpc.call::<u32, u32>("echo", &42).await.unwrap();

select! {
response = call.fuse() => {
println!("Call response: {response:?}")
},
_ = rpc.poll().fuse() => {}
}
}

RPC subscription:

use futures::{select, FutureExt, StreamExt};
use tokio::net::UnixStream;

use karo_common_rpc::rpc::Rpc;

async fn subscribe() {
let stream = UnixStream::connect("/tmp/hub.sock").await.unwrap();
let mut rpc = Rpc::new(stream);

let subscription = rpc.subscribe::<u32>("signal").await.unwrap();

select! {
response = subscription.take(2).collect::<Vec<karo_common_rpc::Result<u32>>>() => {
println!("Subscription response: {response:?}")
},
_ = rpc.poll().fuse() => {}
}
}

Polling imcoming messages:

use futures::{select, FutureExt};
use tokio::net::UnixStream;

use karo_common_rpc::{rpc::Rpc, request::Body};

async fn poll() {
let stream = UnixStream::connect("/tmp/hub.sock").await.unwrap();
let mut rpc = Rpc::new(stream);

loop {
let request = rpc.poll().await;

if request.is_none() {
println!("Client disconnected");
return;
}

let mut request = request.unwrap();

println!("Incoming method call: {}", request.endpoint());
match request.take_body().unwrap() {
Body::Call(bson) => {
println!("Incoming call: {bson:?}");
request.respond(Ok(bson)).await;
},
Body::Subscription => {
println!("Incoming subscription");
request.respond(Ok(41)).await;
request.respond(Ok(42)).await;
request.respond(Ok(43)).await;
},
Body::Fd(client_name, _) => {
println!("Incoming connection request from {client_name}");
request.respond(Ok(())).await;
}
}
}
}

See tests/ for more examples.