p2p: add rpc server to monitor example

3 files changed, 104 insertions, 31 deletions

diff --git a/p2p/Cargo.toml b/p2p/Cargo.toml
index b0d0232..83df9c0 100644
--- a/p2p/Cargo.toml
+++ b/p2p/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "karyon_p2p"
-description = "A lightweight, extensible, and customizable p2p network stack." 
+description = "A lightweight, extensible, and customizable p2p network stack."
 version.workspace = true
 edition.workspace = true
 homepage.workspace = true
@@ -56,3 +56,5 @@ ctrlc = "3.4.4"
 easy-parallel = "3.3.1"
 env_logger = "0.11.3"
 smol = "2.0.0"
+karyon_jsonrpc = { workspace = true, features = ["ws", "smol"] }
+serde_json = "1.0.117"
diff --git a/p2p/examples/monitor.rs b/p2p/examples/monitor.rs
index 32c8959..5382781 100644
--- a/p2p/examples/monitor.rs
+++ b/p2p/examples/monitor.rs
@@ -3,14 +3,17 @@ mod shared;
 use std::sync::Arc;
 
 use clap::Parser;
+use log::error;
 use smol::{channel, Executor};
 
 use karyon_p2p::{
     endpoint::{Endpoint, Port},
     keypair::{KeyPair, KeyPairType},
-    Backend, Config,
+    ArcBackend, Backend, Config,
 };
 
+use karyon_jsonrpc::{rpc_impl, rpc_pubsub_impl, ArcChannel, Server, SubscriptionID};
+
 use shared::run_executor;
 
 #[derive(Parser)]
@@ -20,6 +23,10 @@ struct Cli {
     #[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>,
@@ -33,6 +40,71 @@ struct Cli {
     discovery_port: Option<Port>,
 }
 
+struct MonitorRPC {
+    backend: ArcBackend,
+}
+
+#[rpc_impl]
+impl MonitorRPC {
+    async fn peer_id(
+        &self,
+        _params: serde_json::Value,
+    ) -> Result<serde_json::Value, karyon_jsonrpc::Error> {
+        Ok(serde_json::json!(self.backend.peer_id().to_string()))
+    }
+
+    async fn inbound_connection(
+        &self,
+        _params: serde_json::Value,
+    ) -> Result<serde_json::Value, karyon_jsonrpc::Error> {
+        Ok(serde_json::json!(self.backend.inbound_slots()))
+    }
+
+    async fn outbound_connection(
+        &self,
+        _params: serde_json::Value,
+    ) -> Result<serde_json::Value, karyon_jsonrpc::Error> {
+        Ok(serde_json::json!(self.backend.inbound_slots()))
+    }
+}
+
+#[rpc_pubsub_impl]
+impl MonitorRPC {
+    async fn conn_subscribe(
+        &self,
+        chan: ArcChannel,
+        method: String,
+        _params: serde_json::Value,
+    ) -> Result<serde_json::Value, karyon_jsonrpc::Error> {
+        let sub = chan.new_subscription(&method).await;
+        let sub_id = sub.id.clone();
+        let conn_events = self.backend.monitor().conn_events().await;
+        smol::spawn(async move {
+            loop {
+                let _event = conn_events.recv().await;
+                if let Err(err) = sub.notify(serde_json::json!("event")).await {
+                    error!("Failed to notify: {err}");
+                    break;
+                }
+            }
+        })
+        .detach();
+
+        Ok(serde_json::json!(sub_id))
+    }
+
+    async fn conn_unsubscribe(
+        &self,
+        chan: ArcChannel,
+        _method: String,
+        params: serde_json::Value,
+    ) -> Result<serde_json::Value, karyon_jsonrpc::Error> {
+        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();
@@ -62,44 +134,34 @@ fn main() {
     let exc = ex.clone();
     run_executor(
         async {
-            let monitor = backend.monitor();
-            let conn_listener = monitor.conn_events().await;
-            let peerpool_listener = monitor.peer_pool_events().await;
-            let discovery_listener = monitor.discovery_events().await;
-
-            let monitor_task = exc.spawn(async move {
-                loop {
-                    let event = conn_listener.recv().await.unwrap();
-                    println!("New connection event: {}", event);
-                }
-            });
-
-            let monitor_task2 = exc.spawn(async move {
-                loop {
-                    let event = peerpool_listener.recv().await.unwrap();
-                    println!("New peer pool event: {}", event);
-                }
+            // RPC service
+            let service = Arc::new(MonitorRPC {
+                backend: backend.clone(),
             });
 
-            let monitor_task3 = exc.spawn(async move {
-                loop {
-                    let event = discovery_listener.recv().await.unwrap();
-                    println!("New discovery event: {}", event);
-                }
-            });
+            // Create rpc server
+            let server = Server::builder(cli.rpc_endpoint)
+                .expect("Create server builder")
+                .service(service.clone())
+                .pubsub_service(service)
+                .build_with_executor(exc.clone().into())
+                .await
+                .expect("Build rpc server");
 
             // Run the backend
-            backend.run().await.unwrap();
+            backend.run().await.expect("Run p2p backend");
+
+            // Run the RPC server
+            server.start().await;
 
             // Wait for ctrlc signal
-            ctrlc_r.recv().await.unwrap();
+            ctrlc_r.recv().await.expect("Wait for ctrlc signal");
 
             // Shutdown the backend
             backend.shutdown().await;
 
-            monitor_task.cancel().await;
-            monitor_task2.cancel().await;
-            monitor_task3.cancel().await;
+            // Shutdown the RPC server
+            server.shutdown().await;
         },
         ex,
     );
diff --git a/p2p/src/backend.rs b/p2p/src/backend.rs
index 0db1cee..98297e5 100644
--- a/p2p/src/backend.rs
+++ b/p2p/src/backend.rs
@@ -25,6 +25,9 @@ pub struct Backend {
     /// Identity Key pair
     key_pair: KeyPair,
 
+    /// Peer ID
+    peer_id: PeerID,
+
     /// Responsible for network and system monitoring.
     monitor: Arc<Monitor>,
 
@@ -65,6 +68,7 @@ impl Backend {
 
         Arc::new(Self {
             key_pair: key_pair.clone(),
+            peer_id,
             monitor,
             discovery,
             config,
@@ -97,8 +101,13 @@ impl Backend {
         self.config.clone()
     }
 
+    /// Returns the `PeerID`.
+    pub fn peer_id(&self) -> &PeerID {
+        &self.peer_id
+    }
+
     /// Returns the `KeyPair`.
-    pub async fn key_pair(&self) -> &KeyPair {
+    pub fn key_pair(&self) -> &KeyPair {
         &self.key_pair
     }