futures_util/io/
split.rs

1use std::io;
2
3use {Async, Poll, task};
4use lock::BiLock;
5
6use futures_io::{AsyncRead, AsyncWrite, Error, IoVec};
7
8/// The readable half of an object returned from `AsyncRead::split`.
9#[derive(Debug)]
10pub struct ReadHalf<T> {
11    handle: BiLock<T>,
12}
13
14/// The writable half of an object returned from `AsyncRead::split`.
15#[derive(Debug)]
16pub struct WriteHalf<T> {
17    handle: BiLock<T>,
18}
19
20fn lock_and_then<T, U, E, F>(lock: &BiLock<T>, cx: &mut task::Context, f: F) -> Result<Async<U>, E>
21    where F: FnOnce(&mut T, &mut task::Context) -> Result<Async<U>, E>
22{
23    match lock.poll_lock(cx) {
24        Async::Ready(ref mut l) => f(l, cx),
25        Async::Pending => Ok(Async::Pending),
26    }
27}
28
29pub fn split<T: AsyncRead + AsyncWrite>(t: T) -> (ReadHalf<T>, WriteHalf<T>) {
30    let (a, b) = BiLock::new(t);
31    (ReadHalf { handle: a }, WriteHalf { handle: b })
32}
33
34impl<T: AsyncRead> AsyncRead for ReadHalf<T> {
35    fn poll_read(&mut self, cx: &mut task::Context, buf: &mut [u8])
36        -> Poll<usize, io::Error>
37    {
38        lock_and_then(&self.handle, cx, |l, cx| l.poll_read(cx, buf))
39    }
40
41    fn poll_vectored_read(&mut self, cx: &mut task::Context, vec: &mut [&mut IoVec])
42        -> Poll<usize, io::Error>
43    {
44        lock_and_then(&self.handle, cx, |l, cx| l.poll_vectored_read(cx, vec))
45    }
46}
47
48impl<T: AsyncWrite> AsyncWrite for WriteHalf<T> {
49    fn poll_write(&mut self, cx: &mut task::Context, buf: &[u8])
50        -> Poll<usize, Error>
51    {
52        lock_and_then(&self.handle, cx, |l, cx| l.poll_write(cx, buf))
53    }
54
55    fn poll_vectored_write(&mut self, cx: &mut task::Context, vec: &[&IoVec])
56        -> Poll<usize, Error>
57    {
58        lock_and_then(&self.handle, cx, |l, cx| l.poll_vectored_write(cx, vec))
59    }
60
61    fn poll_flush(&mut self, cx: &mut task::Context) -> Poll<(), Error> {
62        lock_and_then(&self.handle, cx, |l, cx| l.poll_flush(cx))
63    }
64
65    fn poll_close(&mut self, cx: &mut task::Context) -> Poll<(), Error> {
66        lock_and_then(&self.handle, cx, |l, cx| l.poll_close(cx))
67    }
68}
futures_util/io/split.rs

futures_util/io/
split.rs
