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|
use crate::{error::Error, *};
use byteorder::{BigEndian, ReadBytesExt};
use std::{
cell::Cell,
collections::HashMap,
io, result,
sync::{mpsc, Arc, Mutex, Weak},
thread, time,
};
fn to_seqnum(seqnum: u16) -> usize {
(seqnum as usize) & (REL_BUFFER - 1)
}
type PktTx = mpsc::Sender<InPkt>;
type Result = result::Result<(), Error>;
struct Split {
timestamp: time::Instant,
}
struct Chan {
packets: Vec<Cell<Option<Vec<u8>>>>, // in the good old days this used to be called char **
splits: HashMap<u16, Split>,
seqnum: u16,
num: u8,
}
pub struct RecvWorker<R: UdpReceiver, S: UdpSender> {
share: Arc<RudpShare<S>>,
chans: Arc<Vec<Mutex<Chan>>>,
pkt_tx: PktTx,
udp_rx: R,
}
impl<R: UdpReceiver, S: UdpSender> RecvWorker<R, S> {
pub fn new(udp_rx: R, share: Arc<RudpShare<S>>, pkt_tx: PktTx) -> Self {
Self {
udp_rx,
share,
pkt_tx,
chans: Arc::new(
(0..NUM_CHANS as u8)
.map(|num| {
Mutex::new(Chan {
num,
packets: (0..REL_BUFFER).map(|_| Cell::new(None)).collect(),
seqnum: INIT_SEQNUM,
splits: HashMap::new(),
})
})
.collect(),
),
}
}
pub fn run(&self) {
let cleanup_chans = Arc::downgrade(&self.chans);
thread::spawn(move || {
let timeout = time::Duration::from_secs(TIMEOUT);
while let Some(chans) = Weak::upgrade(&cleanup_chans) {
for chan in chans.iter() {
let mut ch = chan.lock().unwrap();
ch.splits = ch
.splits
.drain_filter(|_k, v| v.timestamp.elapsed() < timeout)
.collect();
}
thread::sleep(timeout);
}
});
loop {
if let Err(e) = self.handle(self.recv_pkt()) {
if let Error::LocalDisco = e {
self.share
.send(
PktType::Ctl,
Pkt {
unrel: true,
chan: 0,
data: &[CtlType::Disco as u8],
},
)
.ok();
}
break;
}
}
}
fn recv_pkt(&self) -> Result {
use Error::*;
// todo: reset timeout
let mut cursor = io::Cursor::new(self.udp_rx.recv()?);
let proto_id = cursor.read_u32::<BigEndian>()?;
if proto_id != PROTO_ID {
do yeet InvalidProtoId(proto_id);
}
let peer_id = cursor.read_u16::<BigEndian>()?;
let n_chan = cursor.read_u8()?;
let mut chan = self
.chans
.get(n_chan as usize)
.ok_or(InvalidChannel(n_chan))?
.lock()
.unwrap();
self.process_pkt(cursor, &mut chan)
}
fn process_pkt(&self, mut cursor: io::Cursor<Vec<u8>>, chan: &mut Chan) -> Result {
use CtlType::*;
use Error::*;
use PktType::*;
match cursor.read_u8()?.try_into()? {
Ctl => match cursor.read_u8()?.try_into()? {
Disco => return Err(RemoteDisco),
_ => {}
},
Orig => {
println!("Orig");
self.pkt_tx.send(Ok(Pkt {
chan: chan.num,
unrel: true,
data: cursor.remaining_slice().into(),
}))?;
}
Split => {
println!("Split");
dbg!(cursor.remaining_slice());
}
Rel => {
println!("Rel");
let seqnum = cursor.read_u16::<BigEndian>()?;
chan.packets[to_seqnum(seqnum)].set(Some(cursor.remaining_slice().into()));
while let Some(pkt) = chan.packets[to_seqnum(chan.seqnum)].take() {
self.handle(self.process_pkt(io::Cursor::new(pkt), chan))?;
chan.seqnum = chan.seqnum.overflowing_add(1).0;
}
}
}
Ok(())
}
fn handle(&self, res: Result) -> Result {
use Error::*;
match res {
Ok(v) => Ok(v),
Err(RemoteDisco) => Err(RemoteDisco),
Err(LocalDisco) => Err(LocalDisco),
Err(e) => Ok(self.pkt_tx.send(Err(e))?),
}
}
}
|
