[Add] Pipes (experimental)

example/client/src/main.rs

@@ -1,5 +1,6 @@
 mod auth;
 mod messages;
+mod pipes;
 
 use std::fs;
 use std::path::Path;
@@ -38,6 +39,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let (conn, keyring) = auth::connect_or_register(config, host_public_key, "client").await?;
     messages::send_and_receive(&conn, &keyring, &server_bundle).await?;
 
+    println!("\n--- Pipe demo ---");
+    pipes::run_pipe_demo(&conn, 1).await?;
+
+    conn.sender.close();
     println!("\nDone");
     Ok(())
 }

example/client/src/messages.rs

@@ -96,13 +96,12 @@ pub async fn send_and_receive(
     println!("Sending: {msg}");
     conn.sender.send(&msg).await?;
 
-    match conn.receiver.receive().await {
+    match conn.receive().await {
         Ok(resp) => {
             println!("Received: {resp}");
         }
         Err(e) => eprintln!("Receive error: {e}"),
     }
 
-    conn.sender.close();
     Ok(())
 }

example/client/src/pipes.rs

@@ -0,0 +1,137 @@
+use mtp::client::MTPConnection;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::sync::oneshot;
+use tokio::time::{Duration, Instant};
+
+pub async fn run_pipe_demo(
+    conn: &MTPConnection,
+    iterations: usize,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let sizes = [64, 256, 1024, 4096];
+    let mut all_elapsed = Vec::with_capacity(sizes.len() * iterations);
+    let mut all_data_only = Vec::with_capacity(sizes.len() * iterations);
+
+    for (i, &size) in sizes.iter().enumerate() {
+        let mut size_elapsed = Vec::with_capacity(iterations);
+        let mut size_data_only = Vec::with_capacity(iterations);
+
+        for run in 0..iterations {
+            let random_bytes: Vec<u8> = (0..size).map(|_| rand::random::<u8>()).collect();
+            let description = format!("pipe-demo-{i}-run{run}");
+            println!("  [pipe {i}.{run}] creating pipe ({size} bytes): {description}");
+
+            let handle = conn.create_pipe(&description).await?;
+            let pipe_id = handle.pipe_id();
+            println!("  [pipe {i}.{run}] create_pipe returned (pipe_id={pipe_id})");
+
+            // Overall timer starts before any I/O
+            let overall_start = Instant::now();
+
+            // Channel to capture the instant the writer actually starts writing
+            let (write_start_tx, write_start_rx) = oneshot::channel();
+
+            let write_bytes = random_bytes.clone();
+            let writer_handle = tokio::spawn(async move {
+                println!("  [pipe {i}.{run}] writer: waiting for server accept ...");
+                match handle.wait().await {
+                    Ok(Some(mut writer)) => {
+                        // Record the instant we begin writing
+                        let _ = write_start_tx.send(Instant::now());
+
+                        println!(
+                            "  [pipe {i}.{run}] writer: pipe accepted (pipe_id={pipe_id}), writing {} bytes ...",
+                            write_bytes.len()
+                        );
+                        writer
+                            .write_all(&write_bytes)
+                            .await
+                            .map_err(|e| mtp::common::PipeError::IoError(e.to_string()))?;
+                        writer
+                            .finish()
+                            .await
+                            .map_err(|e| mtp::common::PipeError::IoError(e.to_string()))?;
+                        println!("  [pipe {i}.{run}] writer: data sent and finished");
+                        Ok::<(), mtp::common::PipeError>(())
+                    }
+                    Ok(None) => {
+                        eprintln!("  [pipe {i}.{run}] writer: pipe denied by server");
+                        Err(mtp::common::PipeError::Rejected)
+                    }
+                    Err(e) => {
+                        eprintln!("  [pipe {i}.{run}] writer: error: {e}");
+                        Err(e)
+                    }
+                }
+            });
+
+            println!("  [pipe {i}.{run}] waiting for server's return pipe via receive_pipe() ...");
+            let pipe_req = conn.receive_pipe().await?;
+            println!(
+                "  [pipe {i}.{run}] received return pipe: id={} desc={:?}",
+                pipe_req.id(),
+                pipe_req.description()
+            );
+
+            let mut reader = pipe_req.accept().await?;
+            println!("  [pipe {i}.{run}] return pipe accepted, reading data ...");
+
+            let mut buf = Vec::new();
+            reader.read_to_end(&mut buf).await?;
+            let overall_elapsed = overall_start.elapsed();
+
+            // Receive the instant the writer started writing
+            let data_start = write_start_rx.await?;
+            let data_only_elapsed = Instant::now() - data_start;
+
+            match writer_handle.await {
+                Ok(Ok(())) => {}
+                Ok(Err(e)) => eprintln!("  [pipe {i}.{run}] writer error: {e}"),
+                Err(e) => eprintln!("  [pipe {i}.{run}] writer task panicked: {e}"),
+            }
+
+            let matches = buf == random_bytes;
+            println!(
+                "  [pipe {i}.{run}] round-trip: {} bytes, \
+                 total={:.3}ms, data-only={:.3}ms, match={matches}",
+                size,
+                overall_elapsed.as_secs_f64() * 1000.0,
+                data_only_elapsed.as_secs_f64() * 1000.0,
+            );
+
+            size_elapsed.push(overall_elapsed);
+            size_data_only.push(data_only_elapsed);
+            all_elapsed.push(overall_elapsed);
+            all_data_only.push(data_only_elapsed);
+        }
+
+        // ---- per-size averages ----
+        let avg_total = average_duration(&size_elapsed);
+        let avg_data = average_duration(&size_data_only);
+        println!(
+            "  [pipe {i}] AVERAGE for size {size}: \
+             total={avg_total:.3}ms, data-only={avg_data:.3}ms \
+             (over {iterations} runs)"
+        );
+    }
+
+    // ---- overall averages ----
+    let overall_total = average_duration(&all_elapsed);
+    let overall_data = average_duration(&all_data_only);
+    println!(
+        "  [summary] OVERALL AVERAGE loopback time: \
+         total={overall_total:.3}ms, data-only={overall_data:.3}ms \
+         ({} measurements)",
+        all_elapsed.len()
+    );
+
+    Ok(())
+}
+
+/// Helper: average a slice of Durations without overflowing.
+fn average_duration(durations: &[Duration]) -> f64 {
+    if durations.is_empty() {
+        return 0.0;
+    }
+    let sum_ms: f64 = durations.iter().map(|d| d.as_secs_f64() * 1000.0).sum();
+    sum_ms / durations.len() as f64
+}