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::mem; |
7 | use std::pin::Pin; |
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> { |
22 | 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 | |
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: bool, used: usize) = { |
36 | let available: &[u8] = ready!(reader.as_mut().poll_fill_buf(cx))?; |
37 | if let Some(i: usize) = memchr::memchr(needle:byte, haystack: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(amt:used); |
46 | *read += used; |
47 | if done || used == 0 { |
48 | return Poll::Ready(Ok(mem::replace(dest:read, src:0))); |
49 | } |
50 | } |
51 | } |
52 | |
53 | impl<R: AsyncBufRead + ?Sized + Unpin> Future for ReadUntil<'_, R> { |
54 | type Output = io::Result<usize>; |
55 | |
56 | fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { |
57 | let Self { reader: &mut &mut R, byte: &mut u8, buf: &mut &mut Vec, read: &mut usize } = &mut *self; |
58 | read_until_internal(reader:Pin::new(pointer:reader), cx, *byte, buf, read) |
59 | } |
60 | } |
61 | |