client: add exmaple of how to use custom transports

wayrs-client/examples/custom_transport.rs

@@ -0,0 +1,87 @@
+//! An example of how to use your own custom transport implementation.
+//! Here, the transport keeps track of how much bytes were sent/received.
+
+use std::collections::VecDeque;
+use std::env;
+use std::io;
+use std::os::fd::{OwnedFd, RawFd};
+use std::os::unix::net::UnixStream;
+use std::path::PathBuf;
+
+use wayrs_client::core::transport::Transport;
+use wayrs_client::protocol::wl_registry;
+use wayrs_client::{ConnectionBuilder, IoMode};
+
+fn main() {
+    let mut conn = ConnectionBuilder::with_transport(MyTransport::connect()).build();
+
+    conn.add_registry_cb(|_conn, _state, event| match event {
+        wl_registry::Event::Global(g) => println!(
+            "global ({}) {} added",
+            g.name,
+            g.interface.to_string_lossy(),
+        ),
+        wl_registry::Event::GlobalRemove(name) => println!("global ({name}) removed"),
+        _ => unreachable!(),
+    });
+
+    loop {
+        conn.flush(IoMode::Blocking).unwrap();
+        conn.recv_events(IoMode::Blocking).unwrap();
+        conn.dispatch_events(&mut ());
+
+        let t = conn.transport::<MyTransport>().unwrap();
+        eprintln!("up: {}b down: {}b", t.bytes_sent, t.bytes_read);
+    }
+}
+
+struct MyTransport {
+    socket: UnixStream,
+    bytes_read: usize,
+    bytes_sent: usize,
+}
+
+impl Transport for MyTransport {
+    fn pollable_fd(&self) -> RawFd {
+        self.socket.pollable_fd()
+    }
+
+    fn send(
+        &mut self,
+        bytes: &[std::io::IoSlice],
+        fds: &[OwnedFd],
+        mode: IoMode,
+    ) -> io::Result<usize> {
+        let n = self.socket.send(bytes, fds, mode)?;
+        self.bytes_sent += n;
+        Ok(n)
+    }
+
+    fn recv(
+        &mut self,
+        bytes: &mut [std::io::IoSliceMut],
+        fds: &mut VecDeque<OwnedFd>,
+        mode: IoMode,
+    ) -> io::Result<usize> {
+        let n = self.socket.recv(bytes, fds, mode)?;
+        self.bytes_read += n;
+        Ok(n)
+    }
+}
+
+impl MyTransport {
+    fn connect() -> Self {
+        let runtime_dir = env::var_os("XDG_RUNTIME_DIR").unwrap();
+        let wayland_disp = env::var_os("WAYLAND_DISPLAY").unwrap();
+
+        let mut path = PathBuf::new();
+        path.push(runtime_dir);
+        path.push(wayland_disp);
+
+        Self {
+            socket: UnixStream::connect(path).unwrap(),
+            bytes_read: 0,
+            bytes_sent: 0,
+        }
+    }
+}