wasm_ws/
stream_io.rs

1// Copyright (c) 2019-2022 Naja Melan
2// Copyright (c) 2023-2024 Yuki Kishimoto
3// Distributed under the MIT software license
4
5use std::io;
6use std::io::ErrorKind;
7use std::pin::Pin;
8use std::task::{Context, Poll};
9
10use futures::prelude::{Sink, Stream};
11
12use crate::{WsErr, WsStream};
13
14/// A wrapper around WsStream that converts errors into io::Error so that it can be
15/// used for io (like `AsyncRead`/`AsyncWrite`).
16///
17/// You shouldn't need to use this manually. It is passed to [`IoStream`] when calling
18/// [`WsStream::into_io`].
19//
20#[derive(Debug)]
21//
22pub struct WsStreamIo {
23    inner: WsStream,
24}
25
26impl WsStreamIo {
27    /// Create a new WsStreamIo.
28    //
29    pub fn new(inner: WsStream) -> Self {
30        Self { inner }
31    }
32}
33
34impl Stream for WsStreamIo {
35    type Item = Result<Vec<u8>, io::Error>;
36
37    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
38        Pin::new(&mut self.inner).poll_next(cx).map(|opt| {
39            opt.map(|msg| {
40                msg.map(|m| m.into())
41                    .map_err(|e| io::Error::new(ErrorKind::Other, e))
42            })
43        })
44    }
45}
46
47impl Sink<Vec<u8>> for WsStreamIo {
48    type Error = io::Error;
49
50    fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
51        Pin::new(&mut self.inner)
52            .poll_ready(cx)
53            .map(convert_res_tuple)
54    }
55
56    fn start_send(mut self: Pin<&mut Self>, item: Vec<u8>) -> Result<(), Self::Error> {
57        Pin::new(&mut self.inner)
58            .start_send(item.into())
59            .map_err(convert_err)
60    }
61
62    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
63        Pin::new(&mut self.inner)
64            .poll_flush(cx)
65            .map(convert_res_tuple)
66    }
67
68    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
69        Pin::new(&mut self.inner)
70            .poll_close(cx)
71            .map(convert_res_tuple)
72    }
73}
74
75fn convert_res_tuple(res: Result<(), WsErr>) -> Result<(), io::Error> {
76    res.map_err(convert_err)
77}
78
79fn convert_err(err: WsErr) -> io::Error {
80    match err {
81        WsErr::ConnectionNotOpen => io::Error::from(io::ErrorKind::NotConnected),
82        // This shouldn't happen, so panic for early detection.
83        _ => io::Error::from(io::ErrorKind::Other),
84    }
85}
wasm_ws/stream_io.rs

wasm_ws/
stream_io.rs
