3 files changed, 414 insertions, 0 deletions
diff --git a/p2p/examples/monitor/src/client.rs b/p2p/examples/monitor/src/client.rs
new file mode 100644
index 0000000..d4970eb
--- /dev/null
+++ b/p2p/examples/monitor/src/client.rs
@@ -0,0 +1,48 @@
+use clap::Parser;
+
+use karyon_jsonrpc::Client;
+use karyon_p2p::endpoint::Endpoint;
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+struct Cli {
+    /// RPC server endpoint.
+    #[arg(short)]
+    rpc_endpoint: Endpoint,
+}
+
+fn main() {
+    smol::block_on(async {
+        env_logger::init();
+        let cli = Cli::parse();
+
+        let rpc = Client::builder(cli.rpc_endpoint)
+            .expect("Create rpc client builder")
+            .build()
+            .await
+            .expect("Create rpc client");
+
+        let (_, sub) = rpc
+            .subscribe("MonitorRPC.conn_subscribe", ())
+            .await
+            .expect("Subscribe to connection events");
+
+        let (_, sub2) = rpc
+            .subscribe("MonitorRPC.peer_pool_subscribe", ())
+            .await
+            .expect("Subscribe to peer pool events");
+
+        smol::spawn(async move {
+            loop {
+                let _event = sub.recv().await.expect("Receive connection event");
+            }
+        })
+        .detach();
+
+        smol::spawn(async move {
+            loop {
+                let _event = sub2.recv().await.expect("Receive peer pool event");
+            }
+        }).await;
+    });
+}
diff --git a/p2p/examples/monitor/src/main.rs b/p2p/examples/monitor/src/main.rs
new file mode 100644
index 0000000..636d652
--- /dev/null
+++ b/p2p/examples/monitor/src/main.rs
@@ -0,0 +1,335 @@
+mod shared;
+
+use std::sync::Arc;
+
+use clap::Parser;
+use log::error;
+use ringbuffer::{AllocRingBuffer, RingBuffer};
+use serde::{Deserialize, Serialize};
+use smol::{channel, lock::Mutex, Executor};
+
+use karyon_core::async_util::{CondWait, TaskGroup, TaskResult};
+use karyon_jsonrpc::{rpc_impl, rpc_pubsub_impl, ArcChannel, Server, Subscription, SubscriptionID};
+use karyon_p2p::{
+    endpoint::{Endpoint, Port},
+    keypair::{KeyPair, KeyPairType},
+    monitor::{ConnEvent, DiscoveryEvent, PeerPoolEvent},
+    ArcBackend, Backend, Config, Error, Result,
+};
+
+use shared::run_executor;
+
+const EVENT_BUFFER_SIZE: usize = 30;
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+struct Cli {
+    /// Optional list of bootstrap peers to start the seeding process.
+    #[arg(short)]
+    bootstrap_peers: Vec<Endpoint>,
+
+    /// RPC server endpoint.
+    #[arg(short)]
+    rpc_endpoint: Endpoint,
+
+    /// Optional list of peer endpoints for manual connections.
+    #[arg(short)]
+    peer_endpoints: Vec<Endpoint>,
+
+    /// Optional endpoint for accepting incoming connections.
+    #[arg(short)]
+    listen_endpoint: Option<Endpoint>,
+
+    /// Optional TCP/UDP port for the discovery service.
+    #[arg(short)]
+    discovery_port: Option<Port>,
+}
+
+struct MonitorRPC {
+    backend: ArcBackend,
+    conn_event_buffer: Arc<Mutex<AllocRingBuffer<ConnEvent>>>,
+    pp_event_buffer: Arc<Mutex<AllocRingBuffer<PeerPoolEvent>>>,
+    discv_event_buffer: Arc<Mutex<AllocRingBuffer<DiscoveryEvent>>>,
+    conn_event_condvar: Arc<CondWait>,
+    pp_event_condvar: Arc<CondWait>,
+    discv_event_condvar: Arc<CondWait>,
+    task_group: TaskGroup,
+}
+
+impl MonitorRPC {
+    fn new(backend: ArcBackend, ex: Arc<Executor<'static>>) -> Arc<Self> {
+        Arc::new(MonitorRPC {
+            backend,
+            conn_event_buffer: Arc::new(Mutex::new(AllocRingBuffer::new(EVENT_BUFFER_SIZE))),
+            pp_event_buffer: Arc::new(Mutex::new(AllocRingBuffer::new(EVENT_BUFFER_SIZE))),
+            discv_event_buffer: Arc::new(Mutex::new(AllocRingBuffer::new(EVENT_BUFFER_SIZE))),
+            conn_event_condvar: Arc::new(CondWait::new()),
+            pp_event_condvar: Arc::new(CondWait::new()),
+            discv_event_condvar: Arc::new(CondWait::new()),
+            task_group: TaskGroup::with_executor(ex.into()),
+        })
+    }
+
+    async fn run(&self) -> Result<()> {
+        let conn_events = self.backend.monitor().conn_events().await;
+        let peer_pool_events = self.backend.monitor().peer_pool_events().await;
+        let discovery_events = self.backend.monitor().discovery_events().await;
+
+        let conn_event_buffer = self.conn_event_buffer.clone();
+        let pp_event_buffer = self.pp_event_buffer.clone();
+        let discv_event_buffer = self.discv_event_buffer.clone();
+
+        let conn_event_condvar = self.conn_event_condvar.clone();
+        let pp_event_condvar = self.pp_event_condvar.clone();
+        let discv_event_condvar = self.discv_event_condvar.clone();
+
+        let on_failuer = |res: TaskResult<Result<()>>| async move {
+            if let TaskResult::Completed(Err(err)) = res {
+                error!("Event receive loop: {err}")
+            }
+        };
+
+        self.task_group.spawn(
+            async move {
+                loop {
+                    let event = conn_events.recv().await?;
+                    conn_event_buffer.lock().await.push(event);
+                    conn_event_condvar.broadcast().await;
+                }
+            },
+            on_failuer,
+        );
+
+        self.task_group.spawn(
+            async move {
+                loop {
+                    let event = peer_pool_events.recv().await?;
+                    pp_event_buffer.lock().await.push(event);
+                    pp_event_condvar.broadcast().await;
+                }
+            },
+            on_failuer,
+        );
+
+        self.task_group.spawn(
+            async move {
+                loop {
+                    let event = discovery_events.recv().await?;
+                    discv_event_buffer.lock().await.push(event);
+                    discv_event_condvar.broadcast().await;
+                }
+            },
+            on_failuer,
+        );
+
+        Ok(())
+    }
+
+    async fn shutdown(&self) {
+        self.task_group.cancel().await;
+    }
+}
+
+#[rpc_impl]
+impl MonitorRPC {
+    async fn peer_id(
+        &self,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        Ok(serde_json::json!(self.backend.peer_id().to_string()))
+    }
+
+    async fn inbound_connection(
+        &self,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        Ok(serde_json::json!(self.backend.inbound_slots()))
+    }
+
+    async fn outbound_connection(
+        &self,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        Ok(serde_json::json!(self.backend.outbound_slots()))
+    }
+}
+
+#[rpc_pubsub_impl]
+impl MonitorRPC {
+    async fn conn_subscribe(
+        &self,
+        chan: ArcChannel,
+        method: String,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub = chan.new_subscription(&method).await;
+        let sub_id = sub.id.clone();
+
+        let cond_wait = self.conn_event_condvar.clone();
+        let buffer = self.conn_event_buffer.clone();
+        self.task_group
+            .spawn(notify(sub, cond_wait, buffer), notify_failed);
+
+        Ok(serde_json::json!(sub_id))
+    }
+
+    async fn peer_pool_subscribe(
+        &self,
+        chan: ArcChannel,
+        method: String,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub = chan.new_subscription(&method).await;
+        let sub_id = sub.id.clone();
+
+        let cond_wait = self.pp_event_condvar.clone();
+        let buffer = self.pp_event_buffer.clone();
+        self.task_group
+            .spawn(notify(sub, cond_wait, buffer), notify_failed);
+
+        Ok(serde_json::json!(sub_id))
+    }
+
+    async fn discovery_subscribe(
+        &self,
+        chan: ArcChannel,
+        method: String,
+        _params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub = chan.new_subscription(&method).await;
+        let sub_id = sub.id.clone();
+
+        let cond_wait = self.discv_event_condvar.clone();
+        let buffer = self.discv_event_buffer.clone();
+        self.task_group
+            .spawn(notify(sub, cond_wait, buffer), notify_failed);
+
+        Ok(serde_json::json!(sub_id))
+    }
+
+    async fn conn_unsubscribe(
+        &self,
+        chan: ArcChannel,
+        _method: String,
+        params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub_id: SubscriptionID = serde_json::from_value(params)?;
+        chan.remove_subscription(&sub_id).await;
+        Ok(serde_json::json!(true))
+    }
+
+    async fn peer_pool_unsubscribe(
+        &self,
+        chan: ArcChannel,
+        _method: String,
+        params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub_id: SubscriptionID = serde_json::from_value(params)?;
+        chan.remove_subscription(&sub_id).await;
+        Ok(serde_json::json!(true))
+    }
+
+    async fn discovery_unsubscribe(
+        &self,
+        chan: ArcChannel,
+        _method: String,
+        params: serde_json::Value,
+    ) -> karyon_jsonrpc::Result<serde_json::Value> {
+        let sub_id: SubscriptionID = serde_json::from_value(params)?;
+        chan.remove_subscription(&sub_id).await;
+        Ok(serde_json::json!(true))
+    }
+}
+
+fn main() {
+    env_logger::init();
+    let cli = Cli::parse();
+
+    let key_pair = KeyPair::generate(&KeyPairType::Ed25519);
+
+    // Create the configuration for the backend.
+    let config = Config {
+        listen_endpoint: cli.listen_endpoint,
+        peer_endpoints: cli.peer_endpoints,
+        bootstrap_peers: cli.bootstrap_peers,
+        discovery_port: cli.discovery_port.unwrap_or(0),
+        enable_monitor: true,
+        ..Default::default()
+    };
+
+    // Create a new Executor
+    let ex = Arc::new(Executor::new());
+
+    // Create a new Backend
+    let backend = Backend::new(&key_pair, config, ex.clone().into());
+
+    let (ctrlc_s, ctrlc_r) = channel::unbounded();
+    let handle = move || ctrlc_s.try_send(()).unwrap();
+    ctrlc::set_handler(handle).unwrap();
+
+    let exc = ex.clone();
+    run_executor(
+        async {
+            // RPC service
+            let service = MonitorRPC::new(backend.clone(), exc.clone());
+
+            // Create rpc server
+            let server = Server::builder(cli.rpc_endpoint)
+                .expect("Create server builder")
+                .service(service.clone())
+                .pubsub_service(service.clone())
+                .build_with_executor(exc.clone().into())
+                .await
+                .expect("Build rpc server");
+
+            // Run the RPC server
+            server.start().await;
+
+            // Run the RPC Service
+            service.run().await.expect("Run monitor rpc service");
+
+            // Run the backend
+            backend.run().await.expect("Run p2p backend");
+
+            // Wait for ctrlc signal
+            ctrlc_r.recv().await.expect("Wait for ctrlc signal");
+
+            // Shutdown the backend
+            backend.shutdown().await;
+
+            // Shutdown the RPC server
+            server.shutdown().await;
+
+            // Shutdown the RPC service
+            service.shutdown().await;
+        },
+        ex,
+    );
+}
+
+async fn notify<T: Serialize + Deserialize<'static> + Clone>(
+    sub: Subscription,
+    cond_wait: Arc<CondWait>,
+    buffer: Arc<Mutex<AllocRingBuffer<T>>>,
+) -> Result<()> {
+    for event in buffer.lock().await.iter() {
+        if let Err(err) = sub.notify(serde_json::json!(event)).await {
+            return Err(Error::Other(format!("failed to notify: {err}")));
+        }
+    }
+    loop {
+        cond_wait.wait().await;
+        cond_wait.reset().await;
+        if let Some(event) = buffer.lock().await.back().cloned() {
+            if let Err(err) = sub.notify(serde_json::json!(event)).await {
+                return Err(Error::Other(format!("failed to notify: {err}")));
+            }
+        }
+    }
+}
+
+async fn notify_failed(result: TaskResult<Result<()>>) {
+    if let TaskResult::Completed(Err(err)) = result {
+        error!("Error: {err}");
+    }
+}
diff --git a/p2p/examples/monitor/src/shared.rs b/p2p/examples/monitor/src/shared.rs
new file mode 100644
index 0000000..0e8079c
--- /dev/null
+++ b/p2p/examples/monitor/src/shared.rs
@@ -0,0 +1,31 @@
+use std::{num::NonZeroUsize, sync::Arc, thread};
+
+use easy_parallel::Parallel;
+use smol::{channel, future, future::Future, Executor};
+
+/// Returns an estimate of the default amount of parallelism a program should use.
+/// see `std::thread::available_parallelism`
+pub fn available_parallelism() -> usize {
+    thread::available_parallelism()
+        .map(NonZeroUsize::get)
+        .unwrap_or(1)
+}
+
+/// Run a multi-threaded executor
+pub fn run_executor<T>(main_future: impl Future<Output = T>, ex: Arc<Executor<'_>>) {
+    let (signal, shutdown) = channel::unbounded::<()>();
+
+    let num_threads = available_parallelism();
+
+    Parallel::new()
+        .each(0..(num_threads), |_| {
+            future::block_on(ex.run(shutdown.recv()))
+        })
+        // Run the main future on the current thread.
+        .finish(|| {
+            future::block_on(async {
+                main_future.await;
+                drop(signal);
+            })
+        });
+}