xref: /wasmtime-44.0.1/crates/wasi-http/src/io.rs (revision 0d1efe74)
1 //! I/O utility for bridging between `tokio::io` and `hyper::rt`.
2 
3 use hyper::rt::{Read, ReadBufCursor, Write};
4 use std::io::Error;
5 use std::pin::Pin;
6 use std::task::{Context, Poll};
7 use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
8 
9 /// A type that wraps any type implementing [`tokio::io::AsyncRead`] and [`tokio::io::AsyncWrite`]
10 /// and itself implements [`hyper::rt::Read`] and [`hyper::rt::Write`].
11 #[derive(Debug)]
12 pub struct TokioIo<T> {
13     inner: T,
14 }
15 
16 impl<T> TokioIo<T> {
17     /// Create a new `TokioIo` wrapping the given inner type.
new(inner: T) -> TokioIo<T>18     pub fn new(inner: T) -> TokioIo<T> {
19         TokioIo { inner }
20     }
21 }
22 
23 impl<T: AsyncRead + Unpin> Read for TokioIo<T> {
poll_read( mut self: Pin<&mut Self>, cx: &mut Context<'_>, mut buf: ReadBufCursor<'_>, ) -> Poll<Result<(), Error>>24     fn poll_read(
25         mut self: Pin<&mut Self>,
26         cx: &mut Context<'_>,
27         mut buf: ReadBufCursor<'_>,
28     ) -> Poll<Result<(), Error>> {
29         unsafe {
30             let mut dst = ReadBuf::uninit(buf.as_mut());
31             let res = Pin::new(&mut self.inner).poll_read(cx, &mut dst);
32             let amt = dst.filled().len();
33             buf.advance(amt);
34             res
35         }
36     }
37 }
38 
39 impl<T: AsyncWrite + Unpin> Write for TokioIo<T> {
poll_write( mut self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>40     fn poll_write(
41         mut self: Pin<&mut Self>,
42         cx: &mut Context<'_>,
43         buf: &[u8],
44     ) -> Poll<Result<usize, Error>> {
45         Pin::new(&mut self.inner).poll_write(cx, buf)
46     }
47 
poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>>48     fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
49         Pin::new(&mut self.inner).poll_flush(cx)
50     }
51 
poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>>52     fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Error>> {
53         Pin::new(&mut self.inner).poll_shutdown(cx)
54     }
55 }
56