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tokio-postgres: use tokio mpsc for CopyBoth streams #30

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tokio-postgres: use tokio mpsc for CopyBoth streams #30

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8 changes: 4 additions & 4 deletions tokio-postgres/src/client.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -44,8 +44,8 @@ pub struct Responses {
}

pub struct CopyBothHandles {
pub(crate) stream_receiver: mpsc::Receiver<Result<Message, Error>>,
pub(crate) sink_sender: mpsc::Sender<FrontendMessage>,
pub(crate) stream_receiver: tokio::sync::mpsc::Receiver<Result<Message, Error>>,
pub(crate) sink_sender: tokio::sync::mpsc::Sender<FrontendMessage>,
}

impl Responses {
Expand Down Expand Up @@ -124,8 +124,8 @@ impl InnerClient {

pub fn start_copy_both(&self) -> Result<CopyBothHandles, Error> {
let (sender, receiver) = mpsc::channel(16);
let (stream_sender, stream_receiver) = mpsc::channel(16);
let (sink_sender, sink_receiver) = mpsc::channel(16);
let (stream_sender, stream_receiver) = tokio::sync::mpsc::channel(16);
let (sink_sender, sink_receiver) = tokio::sync::mpsc::channel(16);

let responses = Responses {
receiver,
Expand Down
45 changes: 21 additions & 24 deletions tokio-postgres/src/copy_both.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@ use crate::client::{InnerClient, Responses};
use crate::codec::FrontendMessage;
use crate::{simple_query, Error};
use bytes::{Buf, BufMut, Bytes, BytesMut};
use futures_channel::mpsc;
use futures_util::{ready, Sink, SinkExt, Stream, StreamExt};
use log::debug;
use pin_project_lite::pin_project;
Expand All @@ -12,6 +11,8 @@ use postgres_protocol::message::frontend::CopyData;
use std::marker::{PhantomData, PhantomPinned};
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::sync::mpsc;
use tokio_util::sync::PollSender;

/// The state machine of CopyBothReceiver
///
Expand Down Expand Up @@ -70,7 +71,7 @@ pub struct CopyBothReceiver {
/// Receiver of frontend messages sent by the user using <CopyBothDuplex as Sink>
sink_receiver: mpsc::Receiver<FrontendMessage>,
/// Sender of CopyData contents to be consumed by the user using <CopyBothDuplex as Stream>
stream_sender: mpsc::Sender<Result<Message, Error>>,
stream_sender: PollSender<Result<Message, Error>>,
/// The current state of the subprotocol
state: CopyBothState,
/// Holds a buffered message until we are ready to send it to the user's stream
Expand All @@ -86,7 +87,7 @@ impl CopyBothReceiver {
CopyBothReceiver {
responses,
sink_receiver,
stream_sender,
stream_sender: PollSender::new(stream_sender),
state: CopyBothState::Setup,
buffered_message: None,
}
Expand All @@ -108,10 +109,10 @@ impl CopyBothReceiver {
// Deliver the buffered message (if any) to the user to ensure we can potentially
// buffer a new one in response to a server message
if let Some(message) = self.buffered_message.take() {
match self.stream_sender.poll_ready(cx) {
match self.stream_sender.poll_ready_unpin(cx) {
Poll::Ready(_) => {
// If the receiver has hung up we'll just drop the message
let _ = self.stream_sender.start_send(message);
let _ = self.stream_sender.start_send_unpin(message);
}
Poll::Pending => {
// Stash the message and try again later
Expand Down Expand Up @@ -147,7 +148,7 @@ impl CopyBothReceiver {
match self.state {
CopyNone => self.state = CopyComplete,
CopyComplete => {
self.stream_sender.close_channel();
self.stream_sender.close();
self.sink_receiver.close();
self.state = CommandComplete;
}
Expand All @@ -168,7 +169,7 @@ impl CopyBothReceiver {
Some(Ok(Message::ReadyForQuery(_))) => match self.state {
CommandComplete => {
self.sink_receiver.close();
self.stream_sender.close_channel();
self.stream_sender.close();
}
_ => self.unexpected_message(),
},
Expand All @@ -190,7 +191,7 @@ impl Stream for CopyBothReceiver {
match self.poll_backend(cx) {
Poll::Ready(()) => Poll::Ready(None),
Poll::Pending => match self.state {
Setup | CopyBoth | CopyIn => match ready!(self.sink_receiver.poll_next_unpin(cx)) {
Setup | CopyBoth | CopyIn => match ready!(self.sink_receiver.poll_recv(cx)) {
Some(msg) => Poll::Ready(Some(msg)),
None => match self.state {
// The user has cancelled their interest to this CopyBoth query but we're
Expand Down Expand Up @@ -252,9 +253,7 @@ pin_project! {
/// }
/// ```
pub struct CopyBothDuplex<T> {
#[pin]
sink_sender: mpsc::Sender<FrontendMessage>,
#[pin]
sink_sender: PollSender<FrontendMessage>,
stream_receiver: mpsc::Receiver<Result<Message, Error>>,
buf: BytesMut,
#[pin]
Expand All @@ -267,7 +266,7 @@ impl<T> Stream for CopyBothDuplex<T> {
type Item = Result<Bytes, Error>;

fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
Poll::Ready(match ready!(self.project().stream_receiver.poll_next(cx)) {
Poll::Ready(match ready!(self.project().stream_receiver.poll_recv(cx)) {
Some(Ok(Message::CopyData(body))) => Some(Ok(body.into_bytes())),
Some(Ok(_)) => Some(Err(Error::unexpected_message())),
Some(Err(err)) => Some(Err(err)),
Expand All @@ -285,7 +284,7 @@ where
fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
self.project()
.sink_sender
.poll_ready(cx)
.poll_ready_unpin(cx)
.map_err(|_| Error::closed())
}

Expand All @@ -309,30 +308,28 @@ where

let data = CopyData::new(data).map_err(Error::encode)?;
this.sink_sender
.start_send(FrontendMessage::CopyData(data))
.start_send_unpin(FrontendMessage::CopyData(data))
.map_err(|_| Error::closed())
}

fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
let mut this = self.project();
let this = self.project();

if !this.buf.is_empty() {
ready!(this.sink_sender.as_mut().poll_ready(cx)).map_err(|_| Error::closed())?;
ready!(this.sink_sender.poll_ready_unpin(cx)).map_err(|_| Error::closed())?;
let data: Box<dyn Buf + Send> = Box::new(this.buf.split().freeze());
let data = CopyData::new(data).map_err(Error::encode)?;
this.sink_sender
.as_mut()
.start_send(FrontendMessage::CopyData(data))
.start_send_unpin(FrontendMessage::CopyData(data))
.map_err(|_| Error::closed())?;
}

this.sink_sender.poll_flush(cx).map_err(|_| Error::closed())
Poll::Ready(Ok(()))
}

fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
ready!(self.as_mut().poll_flush(cx))?;
let mut this = self.as_mut().project();
this.sink_sender.disconnect();
let this = self.as_mut().project();
this.sink_sender.close();
Poll::Ready(Ok(()))
}
}
Expand All @@ -356,14 +353,14 @@ where
.await
.map_err(|_| Error::closed())?;

match handles.stream_receiver.next().await.transpose()? {
match handles.stream_receiver.recv().await.transpose()? {
Some(Message::CopyBothResponse(_)) => {}
_ => return Err(Error::unexpected_message()),
}

Ok(CopyBothDuplex {
stream_receiver: handles.stream_receiver,
sink_sender: handles.sink_sender,
sink_sender: PollSender::new(handles.sink_sender),
buf: BytesMut::new(),
_p: PhantomPinned,
_p2: PhantomData,
Expand Down
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