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use std::{rc::Rc, task::Poll};
use anyhow::Context;
use futures::{
channel::mpsc,
io::{AsyncRead, AsyncWrite},
stream, StreamExt,
};
use js_sys::Reflect;
use log::*;
use send_wrapper::SendWrapper;
use serde::{Deserialize, Serialize};
use wasm_bindgen::{prelude::*, JsCast, JsValue};
use wasm_bindgen_futures::JsFuture;
use web_sys::{
RtcConfiguration, RtcDataChannel, RtcDataChannelEvent, RtcDataChannelType, RtcIceCandidateInit,
RtcIceServer, RtcPeerConnection, RtcPeerConnectionIceEvent, RtcSdpType,
RtcSessionDescriptionInit,
};
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct IceCandidate {
pub candidate: String,
#[serde(rename = "sdpMid")]
pub mid: String,
}
#[derive(Serialize, Deserialize, Debug)]
pub struct SessionDescription {
pub sdp: String,
#[serde(rename = "type")]
pub sdp_type: String,
}
#[derive(Debug, Serialize, Deserialize)]
#[serde(untagged)]
pub enum Message {
RemoteDescription(SessionDescription),
RemoteCandidate(IceCandidate),
}
#[derive(Debug, Clone)]
pub struct RtcConfig {
ice_servers: Vec<String>,
}
impl RtcConfig {
pub fn new<S: AsRef<str>>(ice_servers: &[S]) -> Self {
Self {
ice_servers: ice_servers.iter().map(|s| s.as_ref().to_string()).collect(),
}
}
}
pub struct DataStream {
rx_inbound: mpsc::Receiver<anyhow::Result<Vec<u8>>>,
buf_inbound: Vec<u8>,
_on_message: SendWrapper<Closure<dyn FnMut(web_sys::MessageEvent)>>,
inner: SendWrapper<Rc<RtcDataChannel>>,
}
impl DataStream {
fn new(inner: RtcDataChannel) -> Self {
inner.set_binary_type(RtcDataChannelType::Arraybuffer);
let (mut tx, rx_inbound) = mpsc::channel(32);
let on_message = Closure::wrap(Box::new(move |ev: web_sys::MessageEvent| {
let res = match ev.data().dyn_into::<js_sys::ArrayBuffer>() {
Ok(data) => {
let byte_array: Vec<u8> = js_sys::Uint8Array::new(&data).to_vec();
Ok(byte_array)
}
Err(data) => Err(anyhow::anyhow!(
"Expected ArrayBuffer, received: \"{:?}\"",
data
)),
};
if let Err(e) = tx.try_send(res) {
error!("Error sending via channel: {:?}", e);
}
}) as Box<dyn FnMut(web_sys::MessageEvent)>);
inner.set_onmessage(Some(on_message.as_ref().unchecked_ref()));
Self {
_on_message: SendWrapper::new(on_message),
inner: SendWrapper::new(Rc::new(inner)),
buf_inbound: vec![],
rx_inbound,
}
}
}
impl AsyncRead for DataStream {
fn poll_read(
mut self: std::pin::Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
buf: &mut [u8],
) -> std::task::Poll<std::io::Result<usize>> {
if !self.buf_inbound.is_empty() {
let space = buf.len();
if self.buf_inbound.len() <= space {
let len = self.buf_inbound.len();
buf[..len].copy_from_slice(&self.buf_inbound[..]);
self.buf_inbound.drain(..);
Poll::Ready(Ok(len))
} else {
buf.copy_from_slice(&self.buf_inbound[..space]);
self.buf_inbound.drain(..space);
Poll::Ready(Ok(space))
}
} else {
match self.as_mut().rx_inbound.poll_next_unpin(cx) {
std::task::Poll::Ready(Some(Ok(x))) => {
let space = buf.len();
if x.len() <= space {
buf[..x.len()].copy_from_slice(&x[..]);
Poll::Ready(Ok(x.len()))
} else {
buf.copy_from_slice(&x[..space]);
self.buf_inbound.extend_from_slice(&x[space..]);
Poll::Ready(Ok(space))
}
}
std::task::Poll::Ready(Some(Err(e))) => Poll::Ready(Err(std::io::Error::new(
std::io::ErrorKind::Other,
e.to_string(),
))),
std::task::Poll::Ready(None) => Poll::Ready(Ok(0)),
Poll::Pending => Poll::Pending,
}
}
}
}
impl AsyncWrite for DataStream {
fn poll_write(
mut self: std::pin::Pin<&mut Self>,
_cx: &mut std::task::Context<'_>,
buf: &[u8],
) -> std::task::Poll<Result<usize, std::io::Error>> {
if let Err(e) = self.as_mut().inner.send_with_u8_array(buf) {
Poll::Ready(Err(std::io::Error::new(
std::io::ErrorKind::Other,
format!("{:?}", e),
)))
} else {
Poll::Ready(Ok(buf.len()))
}
}
fn poll_flush(
self: std::pin::Pin<&mut Self>,
_cx: &mut std::task::Context<'_>,
) -> std::task::Poll<Result<(), std::io::Error>> {
Poll::Ready(Ok(()))
}
fn poll_close(
self: std::pin::Pin<&mut Self>,
_cx: &mut std::task::Context<'_>,
) -> std::task::Poll<Result<(), std::io::Error>> {
Poll::Ready(Ok(()))
}
}
pub struct PeerConnection {
inner: SendWrapper<Rc<RtcPeerConnection>>,
sig_tx: mpsc::Sender<Message>,
sig_rx: mpsc::Receiver<Message>,
_on_ice_candidate: SendWrapper<Closure<dyn FnMut(RtcPeerConnectionIceEvent)>>,
}
impl PeerConnection {
pub fn new(
config: &RtcConfig,
(sig_tx, sig_rx): (mpsc::Sender<Message>, mpsc::Receiver<Message>),
) -> anyhow::Result<Self> {
let mut rtc_config = RtcConfiguration::new();
let ice_servers = js_sys::Array::new();
for s in &config.ice_servers {
let mut stun_server = RtcIceServer::new();
let stun_servers = js_sys::Array::new();
stun_servers.push(&JsValue::from(s));
stun_server.urls(&stun_servers);
ice_servers.push(&JsValue::from(&stun_server));
}
rtc_config.ice_servers(&ice_servers);
let inner = RtcPeerConnection::new_with_configuration(&rtc_config)
.map_err(|e| anyhow::anyhow!("Error creating peer connection {:?}", e.as_string()))?;
let mut sig_tx_c = sig_tx.clone();
let on_ice_candidate = Closure::wrap(Box::new(move |ev: RtcPeerConnectionIceEvent| {
if let Some(candidate) = ev.candidate() {
if let Err(e) = sig_tx_c.try_send(Message::RemoteCandidate(IceCandidate {
candidate: candidate.candidate(),
mid: candidate.sdp_mid().unwrap_or_default(),
})) {
error!("Sending via sig_tx failed {:?}", e);
}
}
})
as Box<dyn FnMut(RtcPeerConnectionIceEvent)>);
inner.set_onicecandidate(Some(on_ice_candidate.as_ref().unchecked_ref()));
Ok(Self {
inner: SendWrapper::new(Rc::new(inner)),
sig_rx,
sig_tx,
_on_ice_candidate: SendWrapper::new(on_ice_candidate),
})
}
pub async fn accept(self) -> anyhow::Result<DataStream> {
let Self {
inner,
sig_rx,
mut sig_tx,
..
} = self;
enum Either<A, B> {
Left(A),
Right(B),
}
let (mut tx_open, mut rx_open) = mpsc::channel(1);
let (mut tx_chan, rx_chan) = mpsc::channel(1);
let on_open = Closure::wrap(Box::new(move || {
trace!("Inbound data channel opened");
tx_open.try_send(()).expect("channel diend l226");
}) as Box<dyn FnMut()>);
let on_data_channel = Closure::wrap(Box::new(move |ev: RtcDataChannelEvent| {
trace!("Inbound connection attempt");
let channel = ev.channel();
channel.set_onopen(Some(on_open.as_ref().unchecked_ref()));
if let Err(e) = tx_chan.try_send(channel) {
error!("err sending via channel {:?}", e);
}
}) as Box<dyn FnMut(RtcDataChannelEvent)>);
inner.set_ondatachannel(Some(on_data_channel.as_ref().unchecked_ref()));
let mut s = stream::select(sig_rx.map(Either::Left), rx_chan.map(Either::Right));
while let Some(m) = s.next().await {
match m {
Either::Left(remote_msg) => match remote_msg {
Message::RemoteDescription(desc) => {
if desc.sdp_type == "offer" {
trace!("Received offer from remote");
let mut description = RtcSessionDescriptionInit::new(RtcSdpType::Offer);
description.sdp(&desc.sdp);
JsFuture::from(inner.set_remote_description(&description))
.await
.map_err(|e| {
anyhow::anyhow!("Error setting remote description: {:?}", e)
})?;
let answer = JsFuture::from(inner.create_answer())
.await
.map_err(|e| anyhow::anyhow!("Error creating answer: {:?}", e))?;
let answer_sdp = Reflect::get(&answer, &JsValue::from_str("sdp"))
.map_err(|e| {
anyhow::anyhow!("Error extracting sdp from answer: {:?}", e)
})?
.as_string()
.unwrap();
let mut answer_obj = RtcSessionDescriptionInit::new(RtcSdpType::Answer);
answer_obj.sdp(&answer_sdp);
JsFuture::from(inner.set_local_description(&answer_obj))
.await
.map_err(|e| {
anyhow::anyhow!("Error setting local description: {:?}", e)
})?;
if let Err(e) =
sig_tx.try_send(Message::RemoteDescription(SessionDescription {
sdp_type: "answer".into(),
sdp: answer_sdp,
}))
{
error!("Error sending answer via channel: {:?}", e);
} else {
trace!("Sent answer to remote");
}
}
}
Message::RemoteCandidate(c) => {
let mut cand = RtcIceCandidateInit::new(&c.candidate);
cand.sdp_mid(Some(&c.mid));
JsFuture::from(
inner.add_ice_candidate_with_opt_rtc_ice_candidate_init(Some(&cand)),
)
.await
.map_err(|e| anyhow::anyhow!("Error adding ice candidate: {:?}", e))?;
}
},
Either::Right(dc) => {
inner.set_onicecandidate(None);
inner.set_ondatachannel(None);
rx_open.next().await.context("Waiting for open")?;
dc.set_onopen(None);
return Ok(DataStream::new(dc));
}
}
}
anyhow::bail!("Channel didn't open");
}
pub async fn dial(self, label: &str) -> anyhow::Result<DataStream> {
let Self {
mut sig_tx,
inner,
sig_rx,
..
} = self;
let dc = inner.create_data_channel(label);
enum Either<A, B> {
Left(A),
Right(B),
}
let (mut tx_open, rx_open) = mpsc::channel::<()>(1);
let on_open = Closure::wrap(Box::new(move || {
trace!("Outbound Datachannel opened");
if let Err(e) = tx_open.try_send(()) {
error!("Error sending opening event: {:?}", e);
}
}) as Box<dyn FnMut()>);
dc.set_onopen(Some(on_open.as_ref().unchecked_ref()));
let mut s = stream::select(sig_rx.map(Either::Left), rx_open.map(Either::Right));
let offer = JsFuture::from(inner.create_offer())
.await
.map_err(|e| anyhow::anyhow!("Error creating offer: {:?}", e))?;
let offer_sdp = Reflect::get(&offer, &JsValue::from_str("sdp"))
.map_err(|e| anyhow::anyhow!("Error extracting sdp from offer: {:?}", e))?
.as_string()
.unwrap();
let mut offer_obj = RtcSessionDescriptionInit::new(RtcSdpType::Offer);
offer_obj.sdp(&offer_sdp);
let sld_promise = inner.set_local_description(&offer_obj);
JsFuture::from(sld_promise)
.await
.map_err(|e| anyhow::anyhow!("Error setting local description: {:?}", e))?;
sig_tx
.try_send(Message::RemoteDescription(SessionDescription {
sdp_type: "offer".into(),
sdp: offer_sdp,
}))
.context("Signaling channel closed")?;
while let Some(m) = s.next().await {
match m {
Either::Left(remote_msg) => match remote_msg {
Message::RemoteDescription(desc) => {
if desc.sdp_type == "answer" {
let mut description = RtcSessionDescriptionInit::new(
RtcSdpType::from_js_value(&JsValue::from_str(&desc.sdp_type))
.context("Error creating rtc session description")?,
);
description.sdp(&desc.sdp);
JsFuture::from(inner.set_remote_description(&description))
.await
.map_err(|e| {
anyhow::anyhow!("Error setting remote description: {:?}", e)
})?;
}
}
Message::RemoteCandidate(c) => {
let mut cand = RtcIceCandidateInit::new(&c.candidate);
cand.sdp_mid(Some(&c.mid));
JsFuture::from(
inner.add_ice_candidate_with_opt_rtc_ice_candidate_init(Some(&cand)),
)
.await
.map_err(|e| anyhow::anyhow!("Error adding ice candidate: {:?}", e))?;
}
},
Either::Right(_) => {
inner.set_onicecandidate(None);
dc.set_onopen(None);
return Ok(DataStream::new(dc));
}
}
}
anyhow::bail!("Channel didn't open");
}
}