use std::{
collections::VecDeque,
convert::Infallible,
pin::Pin,
task::{Context, Poll},
};
use extend_pinned::ExtendPinned;
use futures_util::{Sink, SinkExt, Stream, TryStream, TryStreamExt, stream::FusedStream};
use pin_project::pin_project;
use ruchei_collections::{
as_linked_slab::{AsLinkedSlab, SlabKey},
linked_slab::LinkedSlab,
};
use ruchei_connection::{Connection, ConnectionWaker, Ready};
use ruchei_extend::{Extending, ExtendingExt};
use crate::connection_item::ConnectionItem;
const OP_WAKE_NEXT: usize = 0;
const OP_WAKE_READY: usize = 1;
const OP_WAKE_FLUSH: usize = 2;
const OP_WAKE_CLOSE: usize = 3;
const OP_IS_STARTED: usize = 4;
const OP_IS_READIED: usize = 5;
const OP_IS_FLUSHING: usize = 6;
const OP_COUNT: usize = 7;
#[pin_project]
#[derive(Debug)]
pub struct Multicast<S, E = <S as TryStream>::Error> {
connections: LinkedSlab<Connection<S>, OP_COUNT>,
#[pin]
next: Ready,
#[pin]
ready: Ready,
#[pin]
flush: Ready,
#[pin]
close: Ready,
closed: VecDeque<(S, Option<E>)>,
}
impl<S, E> Default for Multicast<S, E> {
fn default() -> Self {
Self {
connections: Default::default(),
next: Default::default(),
ready: Default::default(),
flush: Default::default(),
close: Default::default(),
closed: Default::default(),
}
}
}
impl<S, E> Multicast<S, E> {
fn remove(self: Pin<&mut Self>, key: SlabKey, error: Option<E>) {
let this = self.project();
let connection = this.connections.remove(key);
connection.next.wake();
connection.ready.wake();
connection.flush.wake();
connection.close.wake();
this.closed.push_back((connection.stream, error));
this.next.wake();
}
pub fn push(self: Pin<&mut Self>, stream: S) {
let this = self.project();
let key = this.connections.vacant_key();
let next = this.next.downgrade();
let ready = this.ready.downgrade();
let flush = this.flush.downgrade();
let close = this.close.downgrade();
let connection = Connection {
stream,
next: ConnectionWaker::new(key, next),
ready: ConnectionWaker::new(key, ready),
flush: ConnectionWaker::new(key, flush),
close: ConnectionWaker::new(key, close),
};
this.connections.insert_at(key, connection);
this.connections.link_push_back::<OP_WAKE_NEXT>(key);
this.connections.link_push_back::<OP_WAKE_READY>(key);
this.connections.link_push_back::<OP_WAKE_CLOSE>(key);
this.next.wake();
this.ready.wake();
this.close.wake();
}
}
impl<In, E, S: Unpin + TryStream<Ok = In, Error = E>> Stream for Multicast<S, E> {
type Item = ConnectionItem<S>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
let mut this = self.as_mut().project();
if let Some((stream, error)) = this.closed.pop_front() {
return Poll::Ready(Some(ConnectionItem::Closed(stream, error)));
}
this.next.register(cx);
while let Some(key) = this.next.as_mut().next::<OP_WAKE_NEXT>(this.connections) {
if let Some(connection) = this.connections.get_mut(key)
&& let Poll::Ready(o) = connection
.next
.poll(cx, |cx| connection.stream.try_poll_next_unpin(cx))
{
match o {
Some(Ok(item)) => {
this.connections.link_push_back::<OP_WAKE_NEXT>(key);
return Poll::Ready(Some(ConnectionItem::Item(item)));
}
Some(Err(e)) => {
self.as_mut().remove(key, Some(e));
}
None => {
self.as_mut().remove(key, None);
}
}
}
this = self.as_mut().project();
}
if this.connections.is_empty() {
Poll::Ready(None)
} else {
Poll::Pending
}
}
}
impl<In, E, S: Unpin + TryStream<Ok = In, Error = E>> FusedStream for Multicast<S, E> {
fn is_terminated(&self) -> bool {
self.connections.is_empty()
}
}
impl<Out: Clone, E, S: Unpin + Sink<Out, Error = E>> Sink<Out> for Multicast<S, E> {
type Error = Infallible;
fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
let mut this = self.as_mut().project();
this.ready.register(cx);
while let Some(key) = this.ready.as_mut().next::<OP_WAKE_READY>(this.connections) {
if !this.connections.link_contains::<OP_IS_READIED>(key)
&& let Some(connection) = this.connections.get_mut(key)
&& let Poll::Ready(r) = connection
.ready
.poll(cx, |cx| connection.stream.poll_ready_unpin(cx))
{
if let Err(e) = r {
self.as_mut().remove(key, Some(e));
} else {
this.connections.link_push_back::<OP_IS_READIED>(key);
}
}
this = self.as_mut().project();
}
if this.connections.link_len::<OP_IS_READIED>() == this.connections.len() {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
fn start_send(mut self: Pin<&mut Self>, msg: Out) -> Result<(), Self::Error> {
let mut this = self.as_mut().project();
while let Some(key) = this.connections.link_pop_front::<OP_IS_READIED>() {
if let Some(connection) = this.connections.get_mut(key) {
if let Err(e) = connection.stream.start_send_unpin(msg.clone()) {
self.as_mut().remove(key, Some(e));
} else {
this.connections.link_push_back::<OP_IS_STARTED>(key);
if this.connections.link_contains::<OP_IS_FLUSHING>(key) {
this.connections.link_pop_at::<OP_IS_FLUSHING>(key);
this.flush.wake();
}
this.connections.link_push_back::<OP_WAKE_READY>(key);
}
}
this = self.as_mut().project();
}
Ok(())
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
let mut this = self.as_mut().project();
this.flush.register(cx);
this.flush.downgrade().extend(
this.connections
.link_pops::<OP_IS_STARTED, _, _>(|key, _| key),
);
while let Some(key) = this.flush.as_mut().next::<OP_WAKE_FLUSH>(this.connections) {
if let Some(connection) = this.connections.get_mut(key) {
match connection
.flush
.poll(cx, |cx| connection.stream.poll_flush_unpin(cx))
{
Poll::Ready(Ok(())) => {
this.connections.link_pop_at::<OP_IS_FLUSHING>(key);
}
Poll::Ready(Err(e)) => {
self.as_mut().remove(key, Some(e));
}
Poll::Pending => {
this.connections.link_push_back::<OP_IS_FLUSHING>(key);
}
}
}
this = self.as_mut().project();
}
if this.connections.link_empty::<OP_IS_FLUSHING>() {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
let mut this = self.as_mut().project();
this.close.register(cx);
while let Some(key) = this.close.as_mut().next::<OP_WAKE_CLOSE>(this.connections) {
if let Some(connection) = this.connections.get_mut(key)
&& let Poll::Ready(r) = connection
.close
.poll(cx, |cx| connection.stream.poll_close_unpin(cx))
{
match r {
Ok(()) => {
self.as_mut().remove(key, None);
}
Err(e) => {
self.as_mut().remove(key, Some(e));
}
}
}
this = self.as_mut().project();
}
if this.connections.is_empty() {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
}
impl<S, E> ExtendPinned<S> for Multicast<S, E> {
fn extend_pinned<T: IntoIterator<Item = S>>(mut self: Pin<&mut Self>, iter: T) {
for stream in iter {
self.as_mut().push(stream);
}
}
}
pub type MulticastExtending<R> = Extending<Multicast<<R as Stream>::Item>, R>;
pub trait MulticastBufferless: Sized + Stream<Item: Unpin + TryStream> {
#[must_use]
fn multicast_bufferless(self) -> MulticastExtending<Self> {
self.extending_default()
}
}
impl<S: Unpin + TryStream, R: Stream<Item = S>> MulticastBufferless for R {}