Still a work in progress, needs work - but adds a persistent client option for the bus. It currently won't work well without a pause between request/replies - but it works well enough for lqtop. More improvements needed.

src/rust/lqos_bus/benches/socket.rs

@@ -9,6 +9,7 @@ use lqos_bus::*;
 pub fn criterion_benchmark(c: &mut Criterion) {
     c.bench_function("encode_request", |b| {
         let session_to_encode = BusSession {
+            persist: false,
             requests: vec![BusRequest::Ping],
         };
         b.iter(|| {
@@ -19,6 +20,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
 
     c.bench_function("decode_request", |b| {
         let session_to_encode = BusSession {
+            persist: false,
             requests: vec![BusRequest::Ping],
         };
         let msg = encode_request(&session_to_encode).unwrap();
@@ -61,6 +63,14 @@ pub fn criterion_benchmark(c: &mut Criterion) {
             black_box(result);
         });
     });
+
+    c.bench_function("bus_ping_with_persistence", |b| {
+        let mut client = tokio_rt.block_on(BusClient::new()).unwrap();
+        b.iter(|| {
+            let result = tokio_rt.block_on(client.request(vec![BusRequest::Ping])).unwrap();
+            black_box(result);
+        });
+    });
 }
 
 criterion_group!(benches, criterion_benchmark);

src/rust/lqos_bus/src/bus/client.rs

@@ -12,6 +12,7 @@ use anyhow::Result;
 pub async fn bus_request(requests: Vec<BusRequest>) -> Result<Vec<BusResponse>> {
     let mut stream = UnixStream::connect(BUS_SOCKET_PATH).await.unwrap();
     let test = BusSession {
+        persist: false,
         requests,
     };
     let msg = encode_request(&test)?;

src/rust/lqos_bus/src/bus/mod.rs

@@ -3,6 +3,7 @@ mod request;
 mod response;
 mod session;
 mod client;
+mod persistent_client;
 mod unix_socket_server;
 use anyhow::Result;
 pub use reply::BusReply;
@@ -11,6 +12,7 @@ pub use response::BusResponse;
 pub use session::BusSession;
 pub use client::bus_request;
 pub use unix_socket_server::UnixSocketServer;
+pub use persistent_client::BusClient;
 
 /// The local socket path to which `lqosd` will bind itself,
 /// listening for requets.
@@ -45,6 +47,7 @@ mod test {
     #[test]
     fn test_session_roundtrip() {
         let session = BusSession {
+            persist: false,
             requests: vec![BusRequest::Ping],
         };
 

src/rust/lqos_bus/src/bus/persistent_client.rs

@@ -0,0 +1,31 @@
+use anyhow::Result;
+use tokio::{net::UnixStream, io::{AsyncWriteExt, AsyncReadExt}};
+use crate::{BUS_SOCKET_PATH, BusRequest, BusResponse, BusSession, encode_request, decode_response};
+
+pub struct BusClient {
+    stream: UnixStream,
+    buffer: Vec<u8>,
+}
+
+impl BusClient {
+    pub async fn new() -> Result<Self> {
+        let stream = UnixStream::connect(BUS_SOCKET_PATH).await?;
+        Ok(Self {
+            stream,
+            buffer: vec![0u8; 10240],
+        })
+    }
+
+    pub async fn request(&mut self, requests: Vec<BusRequest>) -> Result<Vec<BusResponse>> {
+        let test = BusSession {
+            persist: true,
+            requests,
+        };
+        let msg = encode_request(&test)?;
+        self.stream.write(&msg).await?;
+        self.stream.read(&mut self.buffer).await.unwrap();
+        let reply = decode_response(&self.buffer)?;
+    
+        Ok(reply.responses)
+    }
+}

src/rust/lqos_bus/src/bus/session.rs

@@ -6,6 +6,9 @@ use serde::{Deserialize, Serialize};
 /// which serves as a sanity check that the connection is valid.
 #[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct BusSession {
+    /// Should the session stick around after this request?
+    pub persist: bool,
+
     /// A list of requests to include in this session.
     pub requests: Vec<BusRequest>,
 }

src/rust/lqos_bus/src/bus/unix_socket_server.rs

@@ -38,21 +38,27 @@ impl UnixSocketServer {
         loop {
             let (mut socket, _) = listener.accept().await?;            
             tokio::spawn(async move {
-                let mut buf = vec![0; 1024];
+                loop {
+                    let mut buf = vec![0; 1024];
 
-                let _ = socket
-                    .read(&mut buf)
-                    .await
-                    .expect("failed to read data from socket");
+                    let _bytes_read = socket
+                        .read(&mut buf)
+                        .await
+                        .expect("failed to read data from socket");
 
-                if let Ok(request) = decode_request(&buf) {
-                    let mut response = BusReply {
-                        responses: Vec::new(),
-                    };
-                    handle_bus_requests(&request.requests, &mut response.responses);
-                    let _ = reply_unix(&encode_response(&response).unwrap(), &mut socket).await;
-                } else {
-                    warn!("Invalid data on local socket");
+                    if let Ok(request) = decode_request(&buf) {
+                        let mut response = BusReply {
+                            responses: Vec::new(),
+                        };
+                        handle_bus_requests(&request.requests, &mut response.responses);
+                        let _ = reply_unix(&encode_response(&response).unwrap(), &mut socket).await;
+                        if !request.persist {
+                            break;
+                        }
+                    } else {
+                        warn!("Invalid data on local socket");
+                        break;
+                    }
                 }
             });
         }

src/rust/lqos_bus/src/lib.rs

@@ -17,6 +17,6 @@ mod tc_handle;
 pub use bus::{
     decode_request, decode_response, encode_request, encode_response, BusReply,
     BusRequest, BusResponse, BusSession, BUS_SOCKET_PATH, bus_request,
-    UnixSocketServer,
+    UnixSocketServer, BusClient,
 };
 pub use tc_handle::TcHandle;

src/rust/lqtop/src/main.rs

@@ -1,7 +1,7 @@
 use anyhow::Result;
 use crossterm::{event::KeyCode, terminal::enable_raw_mode};
 use lqos_bus::{
-    BusRequest, BusResponse, IpStats, bus_request,
+    BusRequest, BusResponse, IpStats, bus_request, BusClient,
 };
 use std::{io, time::Duration};
 use tui::{
@@ -18,7 +18,7 @@ struct DataResult {
     top: Vec<IpStats>,
 }
 
-async fn get_data(n_rows: u16) -> Result<DataResult> {
+async fn get_data(client: &mut BusClient, n_rows: u16) -> Result<DataResult> {
     let mut result = DataResult {
         totals: (0, 0, 0, 0),
         top: Vec::new(),
@@ -27,7 +27,7 @@ async fn get_data(n_rows: u16) -> Result<DataResult> {
         BusRequest::GetCurrentThroughput,
         BusRequest::GetTopNDownloaders(n_rows as u32),
     ];
-    for r in bus_request(requests).await? {
+    for r in client.request(requests).await? {
         match r {
             BusResponse::CurrentThroughput {
                 bits_per_second,
@@ -167,6 +167,7 @@ fn draw_top_pane<'a>(
 
 #[tokio::main(flavor = "current_thread")]
 pub async fn main() -> Result<()> {
+    let mut bus_client = BusClient::new().await?;
     let mut packets = (0, 0);
     let mut bits = (0, 0);
     let mut top = Vec::new();
@@ -179,7 +180,7 @@ pub async fn main() -> Result<()> {
     let mut n_rows = 10;
 
     loop {
-        if let Ok(result) = get_data(n_rows).await {
+        if let Ok(result) = get_data(&mut bus_client, n_rows).await {
             let (bits_down, bits_up, packets_down, packets_up) = result.totals;
             packets = (packets_down, packets_up);
             bits = (bits_down, bits_up);