rechunk stream

This commit is contained in:
trinity-1686a 2022-06-05 16:47:29 +02:00
parent 368ba90879
commit fb5462ecdb

View file

@ -53,7 +53,7 @@ pub const PRIO_SECONDARY: RequestPriority = 0x01;
pub(crate) type RequestID = u32;
type ChunkLength = u16;
pub(crate) const MAX_CHUNK_LENGTH: ChunkLength = 0x4000;
const MAX_CHUNK_LENGTH: ChunkLength = 0x4000;
const CHUNK_HAS_CONTINUATION: ChunkLength = 0x8000;
struct SendQueueItem {
@ -77,6 +77,10 @@ enum DataReader {
Streaming {
#[pin]
reader: AssociatedStream,
packet: Vec<u8>,
pos: usize,
buf: Vec<u8>,
eos: bool,
},
}
@ -84,7 +88,13 @@ impl From<Data> for DataReader {
fn from(data: Data) -> DataReader {
match data {
Data::Full(data) => DataReader::Full { data, pos: 0 },
Data::Streaming(reader) => DataReader::Streaming { reader },
Data::Streaming(reader) => DataReader::Streaming {
reader,
packet: Vec::new(),
pos: 0,
buf: Vec::with_capacity(MAX_CHUNK_LENGTH as usize),
eos: false,
},
}
}
}
@ -107,16 +117,43 @@ impl Stream for DataReader {
Poll::Ready(Some((body, len)))
}
}
DataReaderProj::Streaming { reader } => {
reader.poll_next(cx).map(|opt| {
opt.map(|v| {
let mut body = [0; MAX_CHUNK_LENGTH as usize];
let len = std::cmp::min(MAX_CHUNK_LENGTH as usize, v.len());
// TODO this can throw away long vec, they should be splited instead
body[..len].copy_from_slice(&v[..len]);
(body, len)
})
})
DataReaderProj::Streaming {
mut reader,
packet,
pos,
buf,
eos,
} => {
if *eos {
// eos was reached at previous call to poll_next, where a partial packet
// was returned. Now return None
return Poll::Ready(None);
}
loop {
let packet_left = packet.len() - *pos;
let buf_left = MAX_CHUNK_LENGTH as usize - buf.len();
let to_read = std::cmp::min(buf_left, packet_left);
buf.extend_from_slice(&packet[*pos..*pos + to_read]);
*pos += to_read;
if buf.len() == MAX_CHUNK_LENGTH as usize {
// we have a full buf, ready to send
break;
}
// we don't have a full buf, packet is empty; try receive more
if let Some(p) = futures::ready!(reader.as_mut().poll_next(cx)) {
*packet = p;
*pos = 0;
} else {
*eos = true;
break;
}
}
let mut body = [0; MAX_CHUNK_LENGTH as usize];
body[..buf.len()].copy_from_slice(&buf);
buf.clear();
Poll::Ready(Some((body, MAX_CHUNK_LENGTH as usize)))
}
}
}
@ -196,10 +233,7 @@ pub(crate) trait SendLoop: Sync {
data: data.into(),
});
} else if let Some(mut item) = sending.pop() {
trace!(
"send_loop: sending bytes for {}",
item.id,
);
trace!("send_loop: sending bytes for {}", item.id,);
let data = futures::select! {
data = item.data.next().fuse() => data,
@ -210,7 +244,6 @@ pub(crate) trait SendLoop: Sync {
// TODO if every SendQueueItem is waiting on data, use select_all to await
// something to do
// TODO find some way to not require sending empty last chunk
}
};
@ -222,7 +255,7 @@ pub(crate) trait SendLoop: Sync {
None => &[],
};
if !data.is_empty() {
if data.len() == MAX_CHUNK_LENGTH as usize {
let size_header =
ChunkLength::to_be_bytes(data.len() as u16 | CHUNK_HAS_CONTINUATION);
write.write_all(&size_header[..]).await?;
@ -231,7 +264,6 @@ pub(crate) trait SendLoop: Sync {
sending.push(item);
} else {
// this is always zero for now, but may be more when above TODO get fixed
let size_header = ChunkLength::to_be_bytes(data.len() as u16);
write.write_all(&size_header[..]).await?;
@ -267,38 +299,38 @@ pub(crate) trait SendLoop: Sync {
}
struct ChannelPair {
receiver: Option<UnboundedReceiver<Vec<u8>>>,
sender: Option<UnboundedSender<Vec<u8>>>,
receiver: Option<UnboundedReceiver<Vec<u8>>>,
sender: Option<UnboundedSender<Vec<u8>>>,
}
impl ChannelPair {
fn take_receiver(&mut self) -> Option<UnboundedReceiver<Vec<u8>>> {
self.receiver.take()
}
fn take_receiver(&mut self) -> Option<UnboundedReceiver<Vec<u8>>> {
self.receiver.take()
}
fn take_sender(&mut self) -> Option<UnboundedSender<Vec<u8>>> {
self.sender.take()
}
fn take_sender(&mut self) -> Option<UnboundedSender<Vec<u8>>> {
self.sender.take()
}
fn ref_sender(&mut self) -> Option<&UnboundedSender<Vec<u8>>> {
self.sender.as_ref().take()
}
fn ref_sender(&mut self) -> Option<&UnboundedSender<Vec<u8>>> {
self.sender.as_ref().take()
}
fn insert_into(self, map: &mut HashMap<RequestID, ChannelPair>, index: RequestID) {
if self.receiver.is_some() || self.sender.is_some() {
map.insert(index, self);
}
}
fn insert_into(self, map: &mut HashMap<RequestID, ChannelPair>, index: RequestID) {
if self.receiver.is_some() || self.sender.is_some() {
map.insert(index, self);
}
}
}
impl Default for ChannelPair {
fn default() -> Self {
let (send, recv) = unbounded();
ChannelPair {
receiver: Some(recv),
sender: Some(send),
}
}
fn default() -> Self {
let (send, recv) = unbounded();
ChannelPair {
receiver: Some(recv),
sender: Some(send),
}
}
}
/// The RecvLoop trait, which is implemented both by the client and the server
@ -317,10 +349,7 @@ pub(crate) trait RecvLoop: Sync + 'static {
R: AsyncReadExt + Unpin + Send + Sync,
{
let mut receiving: HashMap<RequestID, Vec<u8>> = HashMap::new();
let mut streams: HashMap<
RequestID,
ChannelPair,
> = HashMap::new();
let mut streams: HashMap<RequestID, ChannelPair> = HashMap::new();
loop {
trace!("recv_loop: reading packet");
let mut header_id = [0u8; RequestID::BITS as usize / 8];
@ -345,7 +374,7 @@ pub(crate) trait RecvLoop: Sync + 'static {
trace!("recv_loop: read {} bytes", next_slice.len());
if id & 1 == 0 {
// main stream
// main stream
let mut msg_bytes = receiving.remove(&id).unwrap_or_default();
msg_bytes.extend_from_slice(&next_slice[..]);
@ -357,30 +386,30 @@ pub(crate) trait RecvLoop: Sync + 'static {
if let Some(receiver) = channel_pair.take_receiver() {
self.recv_handler(id, msg_bytes, Box::pin(receiver));
} else {
warn!("Couldn't take receiver part of stream")
}
warn!("Couldn't take receiver part of stream")
}
channel_pair.insert_into(&mut streams, id | 1);
channel_pair.insert_into(&mut streams, id | 1);
}
} else {
// associated stream
let mut channel_pair = streams.remove(&(id)).unwrap_or_default();
// associated stream
let mut channel_pair = streams.remove(&(id)).unwrap_or_default();
// if we get an error, the receiving end is disconnected. We still need to
// reach eos before dropping this sender
if !next_slice.is_empty() {
if let Some(sender) = channel_pair.ref_sender() {
let _ = sender.unbounded_send(next_slice);
} else {
warn!("Couldn't take sending part of stream")
}
}
if !next_slice.is_empty() {
if let Some(sender) = channel_pair.ref_sender() {
let _ = sender.unbounded_send(next_slice);
} else {
warn!("Couldn't take sending part of stream")
}
}
if !has_cont {
channel_pair.take_sender();
}
channel_pair.take_sender();
}
channel_pair.insert_into(&mut streams, id);
channel_pair.insert_into(&mut streams, id);
}
}
Ok(())