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use std::{io::ErrorKind, net::SocketAddr, ops::DerefMut, sync::Arc, task::Poll};
use ahash::{HashMap, HashMapExt};
use anyhow::{Result, anyhow};
use tokio::{
net::UdpSocket,
sync::mpsc::{
Receiver, Sender, UnboundedReceiver, UnboundedSender, channel, unbounded_channel,
},
};
use crate::server::{
memory_pool::{Buffer, MemoryPool},
provider::{ProviderServer, ProviderStream, ServerOptions},
};
pub struct UdpSession {
close_signal_sender: UnboundedSender<SocketAddr>,
bytes_receiver: Receiver<Buffer>,
socket: Arc<UdpSocket>,
addr: SocketAddr,
}
impl ProviderStream for UdpSession {
async fn read(&mut self) -> Result<Buffer> {
self.bytes_receiver
.recv()
.await
.ok_or_else(|| anyhow!("channel closed"))
}
async fn write(&mut self, buffer: &[u8]) -> Result<()> {
if let Err(e) = self.socket.send_to(buffer, self.addr).await {
// Note: An error will also be reported when the remote host is
// shut down, which is not processed yet, but a
// warning will be issued.
if e.kind() != ErrorKind::ConnectionReset {
return Err(e.into());
}
}
Ok(())
}
async fn close(&mut self) {
self.bytes_receiver.close();
let _ = self.close_signal_sender.send(self.addr);
}
}
pub struct UdpServer {
receiver: UnboundedReceiver<UdpSession>,
socket: Arc<UdpSocket>,
}
impl ProviderServer for UdpServer {
type Stream = UdpSession;
async fn bind(options: &ServerOptions) -> Result<Self> {
let socket = Arc::new(UdpSocket::bind(options.listen).await?);
let (socket_sender, socket_receiver) = unbounded_channel::<UdpSession>();
let (close_signal_sender, mut close_signal_receiver) = unbounded_channel::<SocketAddr>();
{
let socket = socket.clone();
tokio::spawn(async move {
let mut sockets = HashMap::<SocketAddr, Sender<Buffer>>::with_capacity(1024);
loop {
let mut buffer = MemoryPool::acquire();
tokio::select! {
ret = socket.recv_buf_from(buffer.deref_mut()) => {
let (size, addr) = match ret {
Ok(it) => it,
// Note: An error will also be reported when the remote host is
// shut down, which is not processed yet, but a
// warning will be issued.
Err(e) => {
if e.kind() != ErrorKind::ConnectionReset {
log::error!("udp server recv_from error={e}");
break;
} else {
continue;
}
}
};
if size < 4 {
continue;
}
if let Some(stream) = sockets.get(&addr) {
if stream.try_send(buffer).is_err()
{
sockets.remove(&addr);
}
} else {
let (tx, bytes_receiver) = channel::<Buffer>(100);
// Send the first packet to the new socket
if tx.try_send(buffer).is_err() {
continue;
}
sockets.insert(addr, tx);
if socket_sender
.send(UdpSession {
close_signal_sender: close_signal_sender.clone(),
socket: socket.clone(),
bytes_receiver,
addr,
})
.is_err()
{
break;
}
}
}
Some(addr) = close_signal_receiver.recv() => {
let _ = sockets.remove(&addr);
}
else => {
break;
}
}
}
});
}
Ok(Self {
receiver: socket_receiver,
socket,
})
}
async fn accept(&mut self) -> Result<Poll<(UdpSession, SocketAddr)>> {
let socket = self
.receiver
.recv()
.await
.ok_or_else(|| anyhow!("channel closed"))?;
let addr = socket.addr;
Ok(Poll::Ready((socket, addr)))
}
fn local_addr(&self) -> Result<SocketAddr> {
Ok(self.socket.local_addr()?)
}
}