From bdf7d4731dcd2e9b523758272fdc41b374044a9f Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Tue, 26 Jul 2022 12:01:13 +0200
Subject: [PATCH] Add stream example to fullmesh example

---
 examples/fullmesh.rs | 133 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 129 insertions(+), 4 deletions(-)

diff --git a/examples/fullmesh.rs b/examples/fullmesh.rs
index 4ab8a8a..82e45c3 100644
--- a/examples/fullmesh.rs
+++ b/examples/fullmesh.rs
@@ -1,17 +1,24 @@
 use std::io::Write;
 use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::Duration;
 
-use log::info;
-
+use async_trait::async_trait;
+use bytes::Bytes;
+use futures::{stream, StreamExt};
+use log::*;
+use serde::{Deserialize, Serialize};
 use structopt::StructOpt;
+use tokio::sync::watch;
 
 use sodiumoxide::crypto::auth;
 use sodiumoxide::crypto::sign::ed25519;
 
+use netapp::endpoint::*;
+use netapp::message::*;
 use netapp::peering::fullmesh::*;
 use netapp::util::*;
-
-use netapp::NetApp;
+use netapp::{NetApp, NodeID};
 
 #[derive(StructOpt, Debug)]
 #[structopt(name = "netapp")]
@@ -92,8 +99,126 @@ async fn main() {
 
 	let watch_cancel = netapp::util::watch_ctrl_c();
 
+	let example = Arc::new(Example {
+		netapp: netapp.clone(),
+		fullmesh: peering.clone(),
+		example_endpoint: netapp.endpoint("__netapp/examples/fullmesh.rs/Example".into()),
+	});
+	example.example_endpoint.set_handler(example.clone());
+
 	tokio::join!(
+		example.exchange_loop(watch_cancel.clone()),
 		netapp.listen(listen_addr, public_addr, watch_cancel.clone()),
 		peering.run(watch_cancel),
 	);
 }
+
+// ----
+
+struct Example {
+	netapp: Arc<NetApp>,
+	fullmesh: Arc<FullMeshPeeringStrategy>,
+	example_endpoint: Arc<Endpoint<ExampleMessage, Self>>,
+}
+
+impl Example {
+	async fn exchange_loop(self: Arc<Self>, must_exit: watch::Receiver<bool>) {
+		let mut i = 12000;
+		while !*must_exit.borrow() {
+			tokio::time::sleep(Duration::from_secs(7)).await;
+
+			let peers = self.fullmesh.get_peer_list();
+			for p in peers.iter() {
+				let id = p.id;
+				if id == self.netapp.id {
+					continue;
+				}
+				i += 1;
+				let example_field = i;
+				let self2 = self.clone();
+				tokio::spawn(async move {
+					info!(
+						"Send example query {} to {}",
+						example_field,
+						hex::encode(id)
+					);
+					let stream =
+						Box::pin(stream::iter([100, 200, 300, 400]).then(|x| async move {
+							tokio::time::sleep(Duration::from_millis(100)).await;
+							Ok(Bytes::from(vec![(x % 256) as u8; 133 * x]))
+						}));
+					match self2
+						.example_endpoint
+						.call_streaming(
+							&id,
+							Req::new(ExampleMessage { example_field })
+								.unwrap()
+								.with_stream(stream),
+							PRIO_NORMAL,
+						)
+						.await
+					{
+						Ok(resp) => {
+							let (resp, stream) = resp.into_parts();
+							info!(
+								"Got example response to {} from {}: {:?}",
+								example_field,
+								hex::encode(id),
+								resp
+							);
+							let mut stream = stream.unwrap();
+							while let Some(x) = stream.next().await {
+								info!("Response: stream got bytes {:?}", x.map(|b| b.len()));
+							}
+						}
+						Err(e) => warn!("Error with example request: {}", e),
+					}
+				});
+			}
+		}
+	}
+}
+
+#[async_trait]
+impl StreamingEndpointHandler<ExampleMessage> for Example {
+	async fn handle(
+		self: &Arc<Self>,
+		mut msg: Req<ExampleMessage>,
+		_from: NodeID,
+	) -> Resp<ExampleMessage> {
+		info!(
+			"Got example message: {:?}, sending example response",
+			msg.msg()
+		);
+		let source_stream = msg.take_stream().unwrap();
+		let new_stream = Box::pin(source_stream.then(|x| async move {
+			info!(
+				"Handler: stream got bytes {:?}",
+				x.as_ref().map(|b| b.len())
+			);
+			tokio::time::sleep(Duration::from_millis(100)).await;
+			Ok(Bytes::from(vec![
+				10u8;
+				x.map(|b| b.len()).unwrap_or(1422) * 2
+			]))
+		}));
+		Resp::new(ExampleResponse {
+			example_field: false,
+		})
+		.with_stream(new_stream)
+	}
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+struct ExampleMessage {
+	example_field: usize,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+struct ExampleResponse {
+	example_field: bool,
+}
+
+impl Message for ExampleMessage {
+	type Response = ExampleResponse;
+}