renet/src/socket/ref_.rs

74 lines
1.8 KiB
Rust

use core::ops::{Deref, DerefMut};
#[cfg(feature = "proto-raw")]
use socket::RawSocket;
#[cfg(feature = "proto-udp")]
use socket::UdpSocket;
#[cfg(feature = "proto-tcp")]
use socket::TcpSocket;
/// A trait for tracking a socket usage session.
///
/// Allows implementation of custom drop logic that runs only if the socket was changed
/// in specific ways. For example, drop logic for UDP would check if the local endpoint
/// has changed, and if yes, notify the socket set.
#[doc(hidden)]
pub trait Session {
fn finish(&mut self) {}
}
#[cfg(feature = "proto-raw")]
impl<'a, 'b> Session for RawSocket<'a, 'b> {}
#[cfg(feature = "proto-udp")]
impl<'a, 'b> Session for UdpSocket<'a, 'b> {}
#[cfg(feature = "proto-tcp")]
impl<'a> Session for TcpSocket<'a> {}
/// A smart pointer to a socket.
///
/// Allows the network stack to efficiently determine if the socket state was changed in any way.
pub struct Ref<'a, T: Session + 'a> {
socket: &'a mut T,
consumed: bool,
}
impl<'a, T: Session> Ref<'a, T> {
pub(crate) fn new(socket: &'a mut T) -> Self {
Ref { socket, consumed: false }
}
}
impl<'a, T: Session + 'a> Ref<'a, T> {
pub(crate) fn map<U, F>(mut ref_: Self, f: F) -> Option<Ref<'a, U>>
where U: Session + 'a, F: FnOnce(&'a mut T) -> Option<&'a mut U> {
if let Some(socket) = f(ref_.socket) {
ref_.consumed = true;
Some(Ref::new(socket))
} else {
None
}
}
}
impl<'a, T: Session> Deref for Ref<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.socket
}
}
impl<'a, T: Session> DerefMut for Ref<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.socket
}
}
impl<'a, T: Session> Drop for Ref<'a, T> {
fn drop(&mut self) {
if !self.consumed {
Session::finish(self.socket);
}
}
}