From 6385e43e8ca467e53c6a705a932016c5af75c3a2 Mon Sep 17 00:00:00 2001
From: cel 🌸 <cel@bunny.garden>
Date: Sun, 22 Dec 2024 18:58:28 +0000
Subject: implement sink and stream with tokio::spawn

---
 jabber/src/jabber_stream/bound_stream.rs | 139 +++++++++++++++++--------------
 1 file changed, 75 insertions(+), 64 deletions(-)

(limited to 'jabber/src/jabber_stream')

diff --git a/jabber/src/jabber_stream/bound_stream.rs b/jabber/src/jabber_stream/bound_stream.rs
index ca93421..c0d67b0 100644
--- a/jabber/src/jabber_stream/bound_stream.rs
+++ b/jabber/src/jabber_stream/bound_stream.rs
@@ -1,70 +1,71 @@
+use std::future::ready;
 use std::pin::pin;
 use std::pin::Pin;
 use std::sync::Arc;
+use std::task::Poll;
 
+use futures::ready;
+use futures::FutureExt;
 use futures::{sink, stream, Sink, Stream};
 use peanuts::{Reader, Writer};
 use pin_project::pin_project;
 use stanza::client::Stanza;
 use tokio::io::{AsyncRead, AsyncWrite, ReadHalf, WriteHalf};
 use tokio::sync::Mutex;
+use tokio::task::JoinHandle;
 
 use crate::Error;
 
 use super::JabberStream;
 
 #[pin_project]
-pub struct BoundJabberStream<R, W, S>
+pub struct BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza>,
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
-    reader: Arc<Mutex<Option<Reader<ReadHalf<S>>>>>,
-    writer: Arc<Mutex<Option<Writer<WriteHalf<S>>>>>,
-    stream: R,
-    sink: W,
+    reader: Arc<Mutex<Reader<ReadHalf<S>>>>,
+    writer: Arc<Mutex<Writer<WriteHalf<S>>>>,
+    write_handle: Option<JoinHandle<Result<(), Error>>>,
+    read_handle: Option<JoinHandle<Result<Stanza, Error>>>,
 }
 
-impl<R, W, S> BoundJabberStream<R, W, S>
+impl<S> BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza>,
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
     // TODO: look into biased mutex, to close stream ASAP
-    pub async fn close_stream(self) -> Result<JabberStream<S>, Error> {
-        if let Some(reader) = self.reader.lock().await.take() {
-            if let Some(writer) = self.writer.lock().await.take() {
-                // TODO: writer </stream:stream>
-                return Ok(JabberStream { reader, writer });
-            }
-        }
-        return Err(Error::StreamClosed);
-    }
+    // TODO: put into connection
+    // pub async fn close_stream(self) -> Result<JabberStream<S>, Error> {
+    //     let reader = self.reader.lock().await.into_self();
+    //     let writer = self.writer.lock().await.into_self();
+    //     // TODO: writer </stream:stream>
+    //     return Ok(JabberStream { reader, writer });
+    // }
 }
 
 pub trait JabberStreamTrait: AsyncWrite + AsyncRead + Unpin + Send {}
 
-impl<R, W, S> Sink<Stanza> for BoundJabberStream<R, W, S>
+impl<S> Sink<Stanza> for BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza> + Unpin,
-    S: AsyncWrite + AsyncRead + Unpin + Send,
+    S: AsyncWrite + AsyncRead + Unpin + Send + 'static,
 {
-    type Error = <W as Sink<Stanza>>::Error;
+    type Error = Error;
 
     fn poll_ready(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
-        let this = self.project();
-        pin!(this.sink).poll_ready(cx)
+        self.poll_flush(cx)
     }
 
     fn start_send(self: std::pin::Pin<&mut Self>, item: Stanza) -> Result<(), Self::Error> {
         let this = self.project();
-        pin!(this.sink).start_send(item)
+        if let Some(_write_handle) = this.write_handle {
+            panic!("start_send called without poll_ready")
+        } else {
+            *this.write_handle = Some(tokio::spawn(write(this.writer.clone(), item)));
+            Ok(())
+        }
     }
 
     fn poll_flush(
@@ -72,32 +73,55 @@ where
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
         let this = self.project();
-        pin!(this.sink).poll_flush(cx)
+        Poll::Ready(if let Some(join_handle) = this.write_handle.as_mut() {
+            match ready!(join_handle.poll_unpin(cx)) {
+                Ok(state) => {
+                    *this.write_handle = None;
+                    state
+                }
+                Err(err) => {
+                    *this.write_handle = None;
+                    Err(err.into())
+                }
+            }
+        } else {
+            Ok(())
+        })
     }
 
     fn poll_close(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
-        let this = self.project();
-        pin!(this.sink).poll_close(cx)
+        self.poll_flush(cx)
     }
 }
 
-impl<R, W, S> Stream for BoundJabberStream<R, W, S>
+impl<S> Stream for BoundJabberStream<S>
 where
-    R: Stream + Unpin,
-    W: Sink<Stanza>,
-    S: AsyncWrite + AsyncRead + Unpin + Send,
+    S: AsyncWrite + AsyncRead + Unpin + Send + 'static,
 {
-    type Item = <R as Stream>::Item;
+    type Item = Result<Stanza, Error>;
 
     fn poll_next(
         self: Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Option<Self::Item>> {
         let this = self.project();
-        pin!(this.stream).poll_next(cx)
+
+        loop {
+            if let Some(join_handle) = this.read_handle.as_mut() {
+                let stanza = ready!(join_handle.poll_unpin(cx));
+                if let Ok(item) = stanza {
+                    *this.read_handle = None;
+                    return Poll::Ready(Some(item));
+                } else if let Err(err) = stanza {
+                    return Poll::Ready(Some(Err(err.into())));
+                }
+            } else {
+                *this.read_handle = Some(tokio::spawn(read(this.reader.clone())))
+            }
+        }
     }
 }
 
@@ -105,49 +129,36 @@ impl<S> JabberStream<S>
 where
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
-    pub fn to_bound_jabber(self) -> BoundJabberStream<impl Stream, impl Sink<Stanza>, S> {
-        let reader = Arc::new(Mutex::new(Some(self.reader)));
-        let writer = Arc::new(Mutex::new(Some(self.writer)));
-        let sink = sink::unfold(writer.clone(), |writer, s: Stanza| async move {
-            write(writer, s).await
-        });
-        let stream = stream::unfold(reader.clone(), |reader| async { read(reader).await });
+    pub fn to_bound_jabber(self) -> BoundJabberStream<S> {
+        let reader = Arc::new(Mutex::new(self.reader));
+        let writer = Arc::new(Mutex::new(self.writer));
         BoundJabberStream {
-            sink,
-            stream,
             writer,
             reader,
+            write_handle: None,
+            read_handle: None,
         }
     }
 }
 
 pub async fn write<W: AsyncWrite + Unpin + Send>(
-    writer: Arc<Mutex<Option<Writer<WriteHalf<W>>>>>,
+    writer: Arc<Mutex<Writer<WriteHalf<W>>>>,
     stanza: Stanza,
-) -> Result<Arc<Mutex<Option<Writer<WriteHalf<W>>>>>, Error> {
+) -> Result<(), Error> {
     {
-        if let Some(writer) = writer.lock().await.as_mut() {
-            writer.write(&stanza).await?;
-        } else {
-            return Err(Error::StreamClosed);
-        }
+        let mut writer = writer.lock().await;
+        writer.write(&stanza).await?;
     }
-    Ok(writer)
+    Ok(())
 }
 
 pub async fn read<R: AsyncRead + Unpin + Send>(
-    reader: Arc<Mutex<Option<Reader<ReadHalf<R>>>>>,
-) -> Option<(
-    Result<Stanza, Error>,
-    Arc<Mutex<Option<Reader<ReadHalf<R>>>>>,
-)> {
+    reader: Arc<Mutex<Reader<ReadHalf<R>>>>,
+) -> Result<Stanza, Error> {
     let stanza: Result<Stanza, Error>;
     {
-        if let Some(reader) = reader.lock().await.as_mut() {
-            stanza = reader.read().await.map_err(|e| e.into());
-        } else {
-            stanza = Err(Error::StreamClosed)
-        };
+        let mut reader = reader.lock().await;
+        stanza = reader.read().await.map_err(|e| e.into());
     }
-    Some((stanza, reader))
+    stanza
 }
-- 
cgit