1 use futures_core::future::Future;
2 use futures_core::ready;
3 use futures_core::task::{Context, Poll};
4 use futures_io::AsyncBufRead;
5 use std::io;
6 use std::pin::Pin;
7 use std::vec::Vec;
8
9 /// Future for the [`read_until`](super::AsyncBufReadExt::read_until) method.
10 #[derive(Debug)]
11 #[must_use = "futures do nothing unless you `.await` or poll them"]
12 pub struct ReadUntil<'a, R: ?Sized> {
13 reader: &'a mut R,
14 byte: u8,
15 buf: &'a mut Vec<u8>,
16 read: usize,
17 }
18
19 impl<R: ?Sized + Unpin> Unpin for ReadUntil<'_, R> {}
20
21 impl<'a, R: AsyncBufRead + ?Sized + Unpin> ReadUntil<'a, R> {
new(reader: &'a mut R, byte: u8, buf: &'a mut Vec<u8>) -> Self22 pub(super) fn new(reader: &'a mut R, byte: u8, buf: &'a mut Vec<u8>) -> Self {
23 Self { reader, byte, buf, read: 0 }
24 }
25 }
26
read_until_internal<R: AsyncBufRead + ?Sized>( mut reader: Pin<&mut R>, cx: &mut Context<'_>, byte: u8, buf: &mut Vec<u8>, read: &mut usize, ) -> Poll<io::Result<usize>>27 pub(super) fn read_until_internal<R: AsyncBufRead + ?Sized>(
28 mut reader: Pin<&mut R>,
29 cx: &mut Context<'_>,
30 byte: u8,
31 buf: &mut Vec<u8>,
32 read: &mut usize,
33 ) -> Poll<io::Result<usize>> {
34 loop {
35 let (done, used) = {
36 let available = ready!(reader.as_mut().poll_fill_buf(cx))?;
37 if let Some(i) = memchr::memchr(byte, available) {
38 buf.extend_from_slice(&available[..=i]);
39 (true, i + 1)
40 } else {
41 buf.extend_from_slice(available);
42 (false, available.len())
43 }
44 };
45 reader.as_mut().consume(used);
46 *read += used;
47 if done || used == 0 {
48 return Poll::Ready(Ok(*read));
49 }
50 }
51 }
52
53 impl<R: AsyncBufRead + ?Sized + Unpin> Future for ReadUntil<'_, R> {
54 type Output = io::Result<usize>;
55
poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>56 fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
57 let Self { reader, byte, buf, read } = &mut *self;
58 read_until_internal(Pin::new(reader), cx, *byte, buf, read)
59 }
60 }
61