1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

//! JSON-RPC websocket client implementation.
use crate::{RpcChannel, RpcError};
use failure::Error;
use futures::prelude::*;
use log::info;
use std::collections::VecDeque;
use websocket::{ClientBuilder, OwnedMessage};

/// Connect to a JSON-RPC websocket server.
///
/// Uses an unbuffered channel to queue outgoing rpc messages.
///
/// Returns `Err` if the `url` is invalid.
pub fn try_connect<T>(url: &str) -> Result<impl Future<Item = T, Error = RpcError>, Error>
where
	T: From<RpcChannel>,
{
	let client_builder = ClientBuilder::new(url)?;
	Ok(do_connect(client_builder))
}

/// Connect to a JSON-RPC websocket server.
///
/// Uses an unbuffered channel to queue outgoing rpc messages.
pub fn connect<T>(url: &url::Url) -> impl Future<Item = T, Error = RpcError>
where
	T: From<RpcChannel>,
{
	let client_builder = ClientBuilder::from_url(url);
	do_connect(client_builder)
}

fn do_connect<T>(client_builder: ClientBuilder) -> impl Future<Item = T, Error = RpcError>
where
	T: From<RpcChannel>,
{
	client_builder
		.async_connect(None)
		.map(|(client, _)| {
			let (sink, stream) = client.split();
			let (sink, stream) = WebsocketClient::new(sink, stream).split();
			let (rpc_client, sender) = super::duplex(sink, stream);
			let rpc_client = rpc_client.map_err(|error| eprintln!("{:?}", error));
			tokio::spawn(rpc_client);
			sender.into()
		})
		.map_err(|error| RpcError::Other(error.into()))
}

struct WebsocketClient<TSink, TStream> {
	sink: TSink,
	stream: TStream,
	queue: VecDeque<OwnedMessage>,
}

impl<TSink, TStream, TError> WebsocketClient<TSink, TStream>
where
	TSink: Sink<SinkItem = OwnedMessage, SinkError = TError>,
	TStream: Stream<Item = OwnedMessage, Error = TError>,
	TError: Into<Error>,
{
	pub fn new(sink: TSink, stream: TStream) -> Self {
		Self {
			sink,
			stream,
			queue: VecDeque::new(),
		}
	}
}

impl<TSink, TStream, TError> Sink for WebsocketClient<TSink, TStream>
where
	TSink: Sink<SinkItem = OwnedMessage, SinkError = TError>,
	TStream: Stream<Item = OwnedMessage, Error = TError>,
	TError: Into<Error>,
{
	type SinkItem = String;
	type SinkError = RpcError;

	fn start_send(&mut self, request: Self::SinkItem) -> Result<AsyncSink<Self::SinkItem>, Self::SinkError> {
		self.queue.push_back(OwnedMessage::Text(request));
		Ok(AsyncSink::Ready)
	}

	fn poll_complete(&mut self) -> Result<Async<()>, Self::SinkError> {
		loop {
			match self.queue.pop_front() {
				Some(request) => match self.sink.start_send(request) {
					Ok(AsyncSink::Ready) => continue,
					Ok(AsyncSink::NotReady(request)) => {
						self.queue.push_front(request);
						break;
					}
					Err(error) => return Err(RpcError::Other(error.into())),
				},
				None => break,
			}
		}
		self.sink.poll_complete().map_err(|error| RpcError::Other(error.into()))
	}
}

impl<TSink, TStream, TError> Stream for WebsocketClient<TSink, TStream>
where
	TSink: Sink<SinkItem = OwnedMessage, SinkError = TError>,
	TStream: Stream<Item = OwnedMessage, Error = TError>,
	TError: Into<Error>,
{
	type Item = String;
	type Error = RpcError;

	fn poll(&mut self) -> Result<Async<Option<Self::Item>>, Self::Error> {
		loop {
			match self.stream.poll() {
				Ok(Async::Ready(Some(message))) => match message {
					OwnedMessage::Text(data) => return Ok(Async::Ready(Some(data))),
					OwnedMessage::Binary(data) => info!("server sent binary data {:?}", data),
					OwnedMessage::Ping(p) => self.queue.push_front(OwnedMessage::Pong(p)),
					OwnedMessage::Pong(_) => {}
					OwnedMessage::Close(c) => self.queue.push_front(OwnedMessage::Close(c)),
				},
				Ok(Async::Ready(None)) => {
					// TODO try to reconnect (#411).
					return Ok(Async::Ready(None));
				}
				Ok(Async::NotReady) => return Ok(Async::NotReady),
				Err(error) => return Err(RpcError::Other(error.into())),
			}
		}
	}
}