feat: tcp transport

- add tcp transport
- refactor examples
- improve proc macro
- add benchmark examples

Cargo.toml

@@ -30,6 +30,8 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 
 [lib]
 
+# [profile.release]
+# debug = true
 
 [[example]]
 name = "channel_sync"
@@ -39,6 +41,18 @@ required-features = ["channel"]
 name = "channel_async"
 required-features = ["channel"]
 
+[[example]]
+name = "channel_sync_benchmark"
+required-features = ["channel"]
+
+[[example]]
+name = "channel_async_benchmark"
+required-features = ["channel"]
+
 [[example]]
 name = "tcp"
 required-features = ["serde"]
+
+[[example]]
+name = "tcp_benchmark"
+required-features = ["serde"]

README.md

@@ -14,7 +14,10 @@ The Server implements read-write locking, there can be many reads at once, but o
 
 The Client object cannot be cloned. Instead all function calls are immutable, so a reference can be shared to all.
 
-Currently only implements local thread messaging. Serialized TCP transport is unfinished.
+Current status:
+- channel_sync : Implementation OK
+- channel_async :  Implementation OK, but beware of performance bottlenecks. If you are making lots of small calls, channel_sync is more fitting
+- tcp : Functional, but server close handling uninmplemented yet
 
 Example:
 ```rs

examples/channel_async.rs

@@ -16,23 +16,16 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     });
 
     let client = TestDataClient::new(c);
-    let clientref = &client;
+
+    let start_time = std::time::Instant::now();
 
     let job1 = async {
         let now = std::time::Instant::now();
-        assert_eq!(DATASIZE, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
-
-        let now = std::time::Instant::now();
-        assert_eq!(267914296, clientref.fib(42).await.unwrap());
+        assert_eq!(267914296, client.fib(42).await.unwrap());
         println!("fib1: {}", dur_to_str(now.elapsed()));
     };
 
     let job2 = async {
-        let now = std::time::Instant::now();
-        assert_eq!(DATASIZE, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
-
         let now = std::time::Instant::now();
         assert_eq!(4, client.calc().await.unwrap().unwrap_or(0));
         println!("calc: {}", dur_to_str(now.elapsed()));
@@ -47,7 +40,11 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         println!("fib2: {}", dur_to_str(now.elapsed()));
 
         let now = std::time::Instant::now();
-        clientref.push((false, TestEnum::NoValue)).await.unwrap();
+        assert_eq!(DATASIZE, client.len().await.unwrap());
+        println!("len: {}", dur_to_str(now.elapsed()));
+
+        let now = std::time::Instant::now();
+        client.push((false, TestEnum::NoValue)).await.unwrap();
         println!("push: {}", dur_to_str(now.elapsed()));
 
         let now = std::time::Instant::now();
@@ -56,6 +53,9 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     };
 
     join!(job1, job2);
+
+    println!("total: {}", dur_to_str(start_time.elapsed()));
+
     client.stop().await.unwrap();
     srv_thread.await.unwrap().unwrap();
 

examples/channel_async_benchmark.rs

@@ -0,0 +1,39 @@
+use futures::{stream::FuturesUnordered, StreamExt};
+use rspc_dev_utilities::test_data::{
+    dur_to_str, make_test_data, TestData, TestDataClient, TestDataServer, CALLS_PER_THREAD,
+    DATASIZE, THREADS,
+};
+
+use rspc::transport;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let (c, s) = transport::channel::new_async();
+    let data: TestData = make_test_data(DATASIZE);
+
+    let srv_thread = tokio::spawn(async move {
+        let mut server = TestDataServer::from(data);
+        server.listen(s).await
+    });
+
+    let client = TestDataClient::new(c);
+
+    let now = std::time::Instant::now();
+    {
+        let set = FuturesUnordered::new();
+        for _ in 0..THREADS {
+            set.push(async {
+                for _ in 0..CALLS_PER_THREAD {
+                    client.heavy_calc().await.unwrap();
+                }
+            });
+        }
+        let _: Vec<_> = set.collect().await;
+    }
+    println!("time: {}", dur_to_str(now.elapsed()));
+
+    client.stop().await.unwrap();
+    srv_thread.await.unwrap().unwrap();
+
+    Ok(())
+}

examples/channel_sync.rs

@@ -1,7 +1,7 @@
+use futures::{stream::FuturesUnordered, StreamExt};
 use rspc_dev_utilities::test_data::{
     dur_to_str, make_test_data, TestData, TestDataClient, TestDataServer, TestEnum, DATASIZE,
 };
-use tokio::join;
 
 use rspc::transport;
 
@@ -16,22 +16,28 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     });
 
     let client = TestDataClient::new(c);
-    let clientref = &client;
 
-    let job1 = async {
+    let start_time = std::time::Instant::now();
+
     let now = std::time::Instant::now();
     assert_eq!(DATASIZE, client.len().await.unwrap());
     println!("len: {}", dur_to_str(now.elapsed()));
 
     let now = std::time::Instant::now();
-        assert_eq!(267914296, clientref.fib(42).await.unwrap());
+    client.push((false, TestEnum::NoValue)).await.unwrap();
+    println!("push: {}", dur_to_str(now.elapsed()));
+
+    let now = std::time::Instant::now();
+    assert_eq!(DATASIZE + 1, client.len().await.unwrap());
+    println!("len: {}", dur_to_str(now.elapsed()));
+
+    let now = std::time::Instant::now();
+    assert_eq!(267914296, client.fib(42).await.unwrap());
     println!("fib1: {}", dur_to_str(now.elapsed()));
-    };
 
-    let job2 = async {
     let now = std::time::Instant::now();
-        assert_eq!(DATASIZE, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
+    assert_eq!(267914296, client.fib(42).await.unwrap());
+    println!("fib2: {}", dur_to_str(now.elapsed()));
 
     let now = std::time::Instant::now();
     assert_eq!(4, client.calc().await.unwrap().unwrap_or(0));
@@ -43,19 +49,21 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     println!("calc_add: {}", dur_to_str(now.elapsed()));
 
     let now = std::time::Instant::now();
-        assert_eq!(267914296, client.fib(42).await.unwrap());
-        println!("fib2: {}", dur_to_str(now.elapsed()));
+    {
+        let set = FuturesUnordered::new();
+        for _ in 0..128 {
+            set.push(async {
+                for _ in 0..100000 {
+                    client.calc().await.unwrap();
+                }
+            });
+        }
+        let _: Vec<_> = set.collect().await;
+    }
+    println!("benchmark: {}", dur_to_str(now.elapsed()));
 
-        let now = std::time::Instant::now();
-        clientref.push((false, TestEnum::NoValue)).await.unwrap();
-        println!("push: {}", dur_to_str(now.elapsed()));
+    println!("total: {}", dur_to_str(start_time.elapsed()));
 
-        let now = std::time::Instant::now();
-        assert_eq!(DATASIZE + 1, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
-    };
-
-    join!(job1, job2);
     client.stop().await.unwrap();
     srv_thread.await.unwrap().unwrap();
 

examples/channel_sync_benchmark.rs

@@ -0,0 +1,39 @@
+use futures::{stream::FuturesUnordered, StreamExt};
+use rspc_dev_utilities::test_data::{
+    dur_to_str, make_test_data, TestData, TestDataClient, TestDataServer, CALLS_PER_THREAD,
+    DATASIZE, THREADS,
+};
+
+use rspc::transport;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let (c, s) = transport::channel::new_sync();
+    let data: TestData = make_test_data(DATASIZE);
+
+    let srv_thread = tokio::spawn(async move {
+        let mut server = TestDataServer::from(data);
+        server.listen(s).await
+    });
+
+    let client = TestDataClient::new(c);
+
+    let now = std::time::Instant::now();
+    {
+        let set = FuturesUnordered::new();
+        for _ in 0..THREADS {
+            set.push(async {
+                for _ in 0..CALLS_PER_THREAD {
+                    client.heavy_calc().await.unwrap();
+                }
+            });
+        }
+        let _: Vec<_> = set.collect().await;
+    }
+    println!("time: {}", dur_to_str(now.elapsed()));
+
+    client.stop().await.unwrap();
+    srv_thread.await.unwrap().unwrap();
+
+    Ok(())
+}

examples/tcp.rs

@@ -1,38 +1,33 @@
+use futures::{stream::FuturesUnordered, StreamExt};
 use rspc_dev_utilities::test_data::{
     dur_to_str, make_test_data, TestData, TestDataClient, TestDataServer, TestEnum, DATASIZE,
 };
 use tokio::join;
 
-use rspc::transport::serde::TcpClient;
-
-use rspc::transport;
+use rspc::transport::serde::{TcpClient, TcpServer};
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let data: TestData = make_test_data(DATASIZE);
+    let mut server = TestDataServer::from(data);
+    let t = TcpServer::new(&"127.0.0.1:6543").await.unwrap();
+    let srv_thread = tokio::spawn(async move { server.listen(t).await });
+
+    tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
+
     let t = TcpClient::connect("127.0.0.1:6543").await.unwrap();
     let client = t.spawn().await;
-
-    // todo : server
-
     let client = TestDataClient::new(client);
 
-    let clientref = &client;
+    let start_time = std::time::Instant::now();
 
     let job1 = async {
         let now = std::time::Instant::now();
-        assert_eq!(DATASIZE, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
-
-        let now = std::time::Instant::now();
-        assert_eq!(267914296, clientref.fib(42).await.unwrap());
+        assert_eq!(267914296, client.fib(42).await.unwrap());
         println!("fib1: {}", dur_to_str(now.elapsed()));
     };
 
     let job2 = async {
-        let now = std::time::Instant::now();
-        assert_eq!(DATASIZE, client.len().await.unwrap());
-        println!("len: {}", dur_to_str(now.elapsed()));
-
         let now = std::time::Instant::now();
         assert_eq!(4, client.calc().await.unwrap().unwrap_or(0));
         println!("calc: {}", dur_to_str(now.elapsed()));
@@ -47,7 +42,11 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         println!("fib2: {}", dur_to_str(now.elapsed()));
 
         let now = std::time::Instant::now();
-        clientref.push((false, TestEnum::NoValue)).await.unwrap();
+        assert_eq!(DATASIZE, client.len().await.unwrap());
+        println!("len: {}", dur_to_str(now.elapsed()));
+
+        let now = std::time::Instant::now();
+        client.push((false, TestEnum::NoValue)).await.unwrap();
         println!("push: {}", dur_to_str(now.elapsed()));
 
         let now = std::time::Instant::now();
@@ -56,7 +55,27 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     };
 
     join!(job1, job2);
+
+    let now = std::time::Instant::now();
+    {
+        let set = FuturesUnordered::new();
+        for _ in 0..128 {
+            set.push(async {
+                for _ in 0..100000 {
+                    client.calc().await.unwrap();
+                }
+            });
+        }
+        let _: Vec<_> = set.collect().await;
+    }
+    println!("benchmark: {}", dur_to_str(now.elapsed()));
+
+    println!("total: {}", dur_to_str(start_time.elapsed()));
+
     client.stop().await.unwrap();
 
+    // todo : server stop
+    srv_thread.await;
+
     Ok(())
 }

examples/tcp_benchmark.rs

@@ -0,0 +1,40 @@
+use futures::{stream::FuturesUnordered, StreamExt};
+use rspc_dev_utilities::test_data::{
+    dur_to_str, make_test_data, TestData, TestDataClient, TestDataServer, CALLS_PER_THREAD,
+    DATASIZE, THREADS,
+};
+
+use rspc::transport::serde::{TcpClient, TcpServer};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let data: TestData = make_test_data(DATASIZE);
+    let mut server = TestDataServer::from(data);
+    let t = TcpServer::new(&"127.0.0.1:6543").await.unwrap();
+    let srv_thread = tokio::spawn(async move { server.listen(t).await });
+
+    tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
+
+    let t = TcpClient::connect("127.0.0.1:6543").await.unwrap();
+    let client = t.spawn().await;
+    let client = TestDataClient::new(client);
+
+    let now = std::time::Instant::now();
+    {
+        let set = FuturesUnordered::new();
+        for _ in 0..THREADS {
+            set.push(async {
+                for _ in 0..CALLS_PER_THREAD {
+                    client.heavy_calc().await.unwrap();
+                }
+            });
+        }
+        let _: Vec<_> = set.collect().await;
+    }
+    println!("time: {}", dur_to_str(now.elapsed()));
+
+    client.stop().await.unwrap();
+    srv_thread.await.unwrap().unwrap();
+
+    Ok(())
+}

macros/src/lib.rs

@@ -316,7 +316,7 @@ pub fn service(_attr: TokenStream, mut input: TokenStream) -> TokenStream {
         impl #server {
             pub async fn listen<Tr>(&mut self, mut transport: Tr) -> Result<(), Tr::Error>
             where
-                Tr: ServerTransporter<#transport_request,#transport_response> + Send
+                Tr: ::rspc::transport::ServerTransporter<#transport_request,#transport_response> + Send
             {
                 {
                     transport.listen( |v,obj| {
@@ -339,14 +339,14 @@ pub fn service(_attr: TokenStream, mut input: TokenStream) -> TokenStream {
 
         pub struct #client<Tr>
         where
-            Tr: ClientTransporter<#transport_request,#transport_response>,
+            Tr: ::rspc::transport::ClientTransporter<#transport_request,#transport_response>,
         {
             transporter: Tr,
         }
 
         impl<Tr> #client<Tr>
         where
-            Tr: ClientTransporter<#transport_request,#transport_response>
+            Tr: ::rspc::transport::ClientTransporter<#transport_request,#transport_response>
         {
             pub fn new(transporter: Tr) -> Self {
                 #client {

src/transport/mod.rs

@@ -37,14 +37,14 @@ pub trait ServerTransporter<T, R> {
 }
 
 pub async fn async_listener<T, R, C, L, LF, S, SF, F, FR, D, E>(
-    listener: &mut L,
+    mut listener: L,
     listener_recv: LF,
-    sender: &mut S,
+    mut sender: S,
     sender_send: SF,
-    handler: F,
-    stop_response: Option<R>,
+    handler: &F,
+    stop_response: &Option<R>,
     userdata: &D,
-) -> Result<(), E>
+) -> Result<bool, E>
 where
     T: Send + Sync,
     R: Send + Sync + 'static,
@@ -55,10 +55,11 @@ where
     SF: Fn(&mut S, (C, R)) -> BoxFuture<Result<(), E>> + Send + Sync + 'static,
     LF: Fn(&mut L) -> BoxFuture<Result<Option<(C, T)>, E>> + 'static,
 {
+    let mut stop = false;
     let mut pending = FuturesUnordered::new();
     loop {
         tokio::select! {
-            rcv = listener_recv(listener) => {
+            rcv = listener_recv(&mut listener) => {
                 match rcv? {
                     Some((id, data)) => {
                         pending.push(
@@ -76,12 +77,14 @@ where
             Some(r) = pending.next() => {
                 match r {
                     (id,Some(r)) => {
-                        sender_send(sender, (id,r)).await?;
+                        sender_send(&mut sender, (id,r)).await?;
                     },
                     (id,None) => {
                         if let Some(v) = stop_response {
-                            sender_send(sender, (id,v)).await?;
+                            todo!() // clone issue on R
+                            // sender_send(&mut sender, (id,v)).await?;
                         }
+                        stop = true;
                         break;
                     },
                 }
@@ -94,11 +97,11 @@ where
     for it in results {
         match it {
             (id, Some(r)) => {
-                sender_send(sender, (id, r)).await?;
+                sender_send(&mut sender, (id, r)).await?;
             }
             _ => (),
         }
     }
 
-    Ok(())
+    Ok(stop)
 }

src/transport/serde.rs

@@ -1,7 +1,7 @@
 use futures::future::BoxFuture;
 use futures::prelude::*;
+use futures::stream::FuturesUnordered;
 use serde::{Deserialize, Serialize};
-use std::net::Ipv4Addr;
 use std::sync::atomic::AtomicUsize;
 use thiserror::Error;
 use tokio::net::{TcpListener, TcpStream};
@@ -115,6 +115,8 @@ where
         })
     }
 
+    /// Turn the TCP Client into a background process and a channel client multiplexer
+    #[cfg(feature = "channel")]
     pub async fn multiplex(
         self,
     ) -> (
@@ -133,6 +135,8 @@ where
         (client, Box::pin(fut))
     }
 
+    /// Spawn a background client multiplexer and give a channel client
+    #[cfg(feature = "channel")]
     pub async fn spawn(self) -> ChannelClient<T, R> {
         let (client, job) = self.multiplex().await;
         tokio::spawn(job);
@@ -140,14 +144,28 @@ where
     }
 }
 
+impl<T, R> ClientTransporter<T, R> for TcpClient<T, R>
+where
+    T: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin + 'static,
+    R: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin + 'static,
+{
+    type Error = Error;
+
+    async fn request(&self, data: T) -> Result<R, Self::Error> {
+        todo!()
+    }
+}
+
 impl<T, R> TcpServer<T, R>
 where
     T: for<'a> Deserialize<'a> + Serialize,
     R: for<'a> Deserialize<'a> + Serialize,
 {
-    pub async fn new(address: &Ipv4Addr, port: u16) -> Result<TcpServer<T, R>, Error> {
-        let address = format!("{}:{}", address, port);
-        let listener = TcpListener::bind(&address).await.map_err(Error::IO)?;
+    pub async fn new<A>(address: &A) -> Result<TcpServer<T, R>, Error>
+    where
+        A: tokio::net::ToSocketAddrs + std::fmt::Display,
+    {
+        let listener = TcpListener::bind(address).await.map_err(Error::IO)?;
         Ok(TcpServer {
             listener,
             ghost: Default::default(),
@@ -156,15 +174,14 @@ where
 
     async fn accept(&mut self) -> Result<TcpStream, Error> {
         let (socket, address) = self.listener.accept().await.map_err(Error::IO)?;
-        println!("connection accepted: {:?}", address);
         Ok(socket)
     }
 }
 
 impl<T, R> ServerTransporter<T, R> for TcpServer<T, R>
 where
-    T: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin,
-    R: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin,
+    T: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin + 'static,
+    R: for<'a> Deserialize<'a> + Serialize + Send + Sync + Unpin + 'static,
 {
     type Error = Error;
 
@@ -176,34 +193,45 @@ where
     ) -> Result<(), Self::Error>
     where
         FR: Future<Output = Option<R>> + Send + 'static,
-        F: Fn(T, &D) -> FR + Send + Sync,
-        D: Send + Sync,
+        F: Fn(T, &D) -> FR + Send + Sync + 'static,
+        D: Send + Sync + 'static,
     {
-        let (client, fut) = channel::new_multiplexer::<R, T>();
-
-        // super::async_listener(
-        //     &mut receiver, |_self| { Box::pin(async {
-        //         _self.recv().await
-        //     }) },
-        //     &mut sender, |_self, data| { Box::pin(async {
-        //         _self.send(data).await
-        //         }) },
-        //     handler, stop_response, &userdata);
-
-        while let Ok(mut stream) = self.accept().await {
+        let mut connections = FuturesUnordered::new();
+        loop {
+            tokio::select! {
+                connect = self.accept() => {
+                    match connect {
+                        Ok(stream) => {
                             let (sender, receiver) = split::<R, T>(stream).await;
-            // tokio::spawn(async move {
-            //     super::async_listener(
-            //         &mut receiver, |_self| { Box::pin(async {
-            //            _self.recv().await
-            //         }) },
-            //         &mut sender, |_self, data| { Box::pin(async {
-            //             _self.send(data).await
-            //          }) },
-            //         handler, stop_response, &userdata)
-            // });
+                            let handler = &handler;
+                            let stop_response = &stop_response;
+                            let userdata = &userdata;
+                            connections.push(async move {
+                                super::async_listener(
+                                    receiver,
+                                    |_self| Box::pin(async { _self.recv().await }),
+                                    sender,
+                                    |_self, data| Box::pin(async { _self.send(data).await }),
+                                    handler,
+                                    stop_response,
+                                    userdata,
+                                ).await
+                            });
+                        },
+                        Err(e) => {
+                            println!("WARN: connection accept error: {e}");
+                        }
+                    }
+                },
+                Some(s) = connections.next() => {
+                    if let Ok(true) = s {
+                        break;
+                    }
+                    // poll connected threads to get them running
+                }
+            }
         }
 
-        todo!()
+        Ok(())
     }
 }

tests/tcp.rs

@@ -0,0 +1,46 @@
+#[cfg(test)]
+#[cfg(feature = "serde")]
+mod tests {
+    // use rspc::transport::{channel, ClientTransporter, ServerTransporter};
+
+    pub struct MyStruct {
+        my_vec: Vec<String>,
+    }
+
+    #[rspc::service]
+    impl MyStruct {
+        pub fn len(&self) -> usize {
+            self.my_vec.len()
+        }
+
+        pub fn push(&mut self, val: String) {
+            self.my_vec.push(val)
+        }
+
+        pub fn pop(&mut self) -> Option<String> {
+            self.my_vec.pop()
+        }
+    }
+
+    #[tokio::test]
+    async fn test() {
+        // let my_data = MyStruct { my_vec: Vec::new() };
+        // let (c, s) = channel::new_sync();
+
+        // let srv_thread = tokio::spawn(async move {
+        //     let mut server = MyStructServer::from(my_data);
+        //     server.listen(s).await
+        // });
+
+        // let client = MyStructClient::new(c);
+        // assert_eq!(client.len().await.unwrap(), 0);
+        // client.push("Hello world!".to_string()).await.unwrap();
+        // assert_eq!(client.len().await.unwrap(), 1);
+        // assert_eq!(
+        //     client.pop().await.unwrap(),
+        //     Some("Hello world!".to_string())
+        // );
+        // client.stop().await.unwrap();
+        // srv_thread.await.unwrap().unwrap();
+    }
+}

utilities/src/test_data.rs

@@ -1,7 +1,5 @@
 use std::time::Duration;
 
-use rspc::transport::{ClientTransporter, ServerTransporter};
-
 use serde::{Deserialize, Serialize};
 
 pub fn dur_to_num(dur: Duration) -> (u128, &'static str) {
@@ -21,7 +19,9 @@ pub fn dur_to_str(dur: Duration) -> String {
     n.to_string() + " " + s
 }
 
-pub const DATASIZE: usize = 1000000;
+pub const DATASIZE: usize = 10000;
+pub const THREADS: usize = 8;
+pub const CALLS_PER_THREAD: usize = 1000;
 
 const TEST_STRINGS: [&str; 4] = ["toto", "tata", "titi", "tutu"];
 
@@ -39,6 +39,10 @@ pub struct TestData {
 
 #[rspc::service]
 impl TestData {
+    pub fn mem_size(&self) -> usize {
+        std::mem::size_of_val(&self.vec)
+    }
+
     pub fn len(&self) -> usize {
         self.vec.len()
     }
@@ -52,6 +56,16 @@ impl TestData {
         return None;
     }
 
+    pub fn heavy_calc(&self) -> usize {
+        let mut res = 0;
+        for v in &self.vec {
+            if let (true, TestEnum::Num(n)) = v {
+                res += n;
+            }
+        }
+        return res;
+    }
+
     pub async fn slow_fct(&self) -> Option<usize> {
         tokio::time::sleep(Duration::from_secs(1)).await;
         self.calc()