| #![warn(rust_2018_idioms)] |
| #![cfg(feature = "full")] |
| |
| // https://github.com/rust-lang/futures-rs/blob/1803948ff091b4eabf7f3bf39e16bbbdefca5cc8/futures/tests/io_buf_reader.rs |
| |
| use futures::task::{noop_waker_ref, Context, Poll}; |
| use std::cmp; |
| use std::io::{self, Cursor}; |
| use std::pin::Pin; |
| use tokio::io::{ |
| AsyncBufRead, AsyncBufReadExt, AsyncRead, AsyncReadExt, AsyncSeek, AsyncSeekExt, AsyncWriteExt, |
| BufReader, ReadBuf, SeekFrom, |
| }; |
| use tokio_test::task::spawn; |
| use tokio_test::{assert_pending, assert_ready}; |
| |
| macro_rules! run_fill_buf { |
| ($reader:expr) => {{ |
| let mut cx = Context::from_waker(noop_waker_ref()); |
| loop { |
| if let Poll::Ready(x) = Pin::new(&mut $reader).poll_fill_buf(&mut cx) { |
| break x; |
| } |
| } |
| }}; |
| } |
| |
| struct MaybePending<'a> { |
| inner: &'a [u8], |
| ready_read: bool, |
| ready_fill_buf: bool, |
| } |
| |
| impl<'a> MaybePending<'a> { |
| fn new(inner: &'a [u8]) -> Self { |
| Self { |
| inner, |
| ready_read: false, |
| ready_fill_buf: false, |
| } |
| } |
| } |
| |
| impl AsyncRead for MaybePending<'_> { |
| fn poll_read( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| buf: &mut ReadBuf<'_>, |
| ) -> Poll<io::Result<()>> { |
| if self.ready_read { |
| self.ready_read = false; |
| Pin::new(&mut self.inner).poll_read(cx, buf) |
| } else { |
| self.ready_read = true; |
| cx.waker().wake_by_ref(); |
| Poll::Pending |
| } |
| } |
| } |
| |
| impl AsyncBufRead for MaybePending<'_> { |
| fn poll_fill_buf(mut self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<&[u8]>> { |
| if self.ready_fill_buf { |
| self.ready_fill_buf = false; |
| if self.inner.is_empty() { |
| return Poll::Ready(Ok(&[])); |
| } |
| let len = cmp::min(2, self.inner.len()); |
| Poll::Ready(Ok(&self.inner[0..len])) |
| } else { |
| self.ready_fill_buf = true; |
| Poll::Pending |
| } |
| } |
| |
| fn consume(mut self: Pin<&mut Self>, amt: usize) { |
| self.inner = &self.inner[amt..]; |
| } |
| } |
| |
| #[tokio::test] |
| async fn test_buffered_reader() { |
| let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; |
| let mut reader = BufReader::with_capacity(2, inner); |
| |
| let mut buf = [0, 0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 3); |
| assert_eq!(buf, [5, 6, 7]); |
| assert_eq!(reader.buffer(), []); |
| |
| let mut buf = [0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 2); |
| assert_eq!(buf, [0, 1]); |
| assert_eq!(reader.buffer(), []); |
| |
| let mut buf = [0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [2]); |
| assert_eq!(reader.buffer(), [3]); |
| |
| let mut buf = [0, 0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [3, 0, 0]); |
| assert_eq!(reader.buffer(), []); |
| |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [4, 0, 0]); |
| assert_eq!(reader.buffer(), []); |
| |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| } |
| |
| #[tokio::test] |
| async fn test_buffered_reader_seek() { |
| let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; |
| let mut reader = BufReader::with_capacity(2, Cursor::new(inner)); |
| |
| assert_eq!(reader.seek(SeekFrom::Start(3)).await.unwrap(), 3); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[0, 1][..]); |
| assert!(reader.seek(SeekFrom::Current(i64::MIN)).await.is_err()); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[0, 1][..]); |
| assert_eq!(reader.seek(SeekFrom::Current(1)).await.unwrap(), 4); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[1, 2][..]); |
| Pin::new(&mut reader).consume(1); |
| assert_eq!(reader.seek(SeekFrom::Current(-2)).await.unwrap(), 3); |
| } |
| |
| #[tokio::test] |
| async fn test_buffered_reader_seek_underflow() { |
| // gimmick reader that yields its position modulo 256 for each byte |
| struct PositionReader { |
| pos: u64, |
| } |
| impl AsyncRead for PositionReader { |
| fn poll_read( |
| mut self: Pin<&mut Self>, |
| _: &mut Context<'_>, |
| buf: &mut ReadBuf<'_>, |
| ) -> Poll<io::Result<()>> { |
| let b = buf.initialize_unfilled(); |
| let len = b.len(); |
| for x in b { |
| *x = self.pos as u8; |
| self.pos = self.pos.wrapping_add(1); |
| } |
| buf.advance(len); |
| Poll::Ready(Ok(())) |
| } |
| } |
| impl AsyncSeek for PositionReader { |
| fn start_seek(mut self: Pin<&mut Self>, pos: SeekFrom) -> io::Result<()> { |
| match pos { |
| SeekFrom::Start(n) => { |
| self.pos = n; |
| } |
| SeekFrom::Current(n) => { |
| self.pos = self.pos.wrapping_add(n as u64); |
| } |
| SeekFrom::End(n) => { |
| self.pos = u64::MAX.wrapping_add(n as u64); |
| } |
| } |
| Ok(()) |
| } |
| fn poll_complete(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<u64>> { |
| Poll::Ready(Ok(self.pos)) |
| } |
| } |
| |
| let mut reader = BufReader::with_capacity(5, PositionReader { pos: 0 }); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[0, 1, 2, 3, 4][..]); |
| assert_eq!(reader.seek(SeekFrom::End(-5)).await.unwrap(), u64::MAX - 5); |
| assert_eq!(run_fill_buf!(reader).unwrap().len(), 5); |
| // the following seek will require two underlying seeks |
| let expected = 9_223_372_036_854_775_802; |
| assert_eq!( |
| reader.seek(SeekFrom::Current(i64::MIN)).await.unwrap(), |
| expected |
| ); |
| assert_eq!(run_fill_buf!(reader).unwrap().len(), 5); |
| // seeking to 0 should empty the buffer. |
| assert_eq!(reader.seek(SeekFrom::Current(0)).await.unwrap(), expected); |
| assert_eq!(reader.get_ref().pos, expected); |
| } |
| |
| #[tokio::test] |
| async fn test_short_reads() { |
| /// A dummy reader intended at testing short-reads propagation. |
| struct ShortReader { |
| lengths: Vec<usize>, |
| } |
| |
| impl AsyncRead for ShortReader { |
| fn poll_read( |
| mut self: Pin<&mut Self>, |
| _: &mut Context<'_>, |
| buf: &mut ReadBuf<'_>, |
| ) -> Poll<io::Result<()>> { |
| if !self.lengths.is_empty() { |
| buf.advance(self.lengths.remove(0)); |
| } |
| Poll::Ready(Ok(())) |
| } |
| } |
| |
| let inner = ShortReader { |
| lengths: vec![0, 1, 2, 0, 1, 0], |
| }; |
| let mut reader = BufReader::new(inner); |
| let mut buf = [0, 0]; |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 1); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 2); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 1); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| } |
| |
| #[tokio::test] |
| async fn maybe_pending() { |
| let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; |
| let mut reader = BufReader::with_capacity(2, MaybePending::new(inner)); |
| |
| let mut buf = [0, 0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 3); |
| assert_eq!(buf, [5, 6, 7]); |
| assert_eq!(reader.buffer(), []); |
| |
| let mut buf = [0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 2); |
| assert_eq!(buf, [0, 1]); |
| assert_eq!(reader.buffer(), []); |
| |
| let mut buf = [0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [2]); |
| assert_eq!(reader.buffer(), [3]); |
| |
| let mut buf = [0, 0, 0]; |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [3, 0, 0]); |
| assert_eq!(reader.buffer(), []); |
| |
| let nread = reader.read(&mut buf).await.unwrap(); |
| assert_eq!(nread, 1); |
| assert_eq!(buf, [4, 0, 0]); |
| assert_eq!(reader.buffer(), []); |
| |
| assert_eq!(reader.read(&mut buf).await.unwrap(), 0); |
| } |
| |
| #[tokio::test] |
| async fn maybe_pending_buf_read() { |
| let inner = MaybePending::new(&[0, 1, 2, 3, 1, 0]); |
| let mut reader = BufReader::with_capacity(2, inner); |
| let mut v = Vec::new(); |
| reader.read_until(3, &mut v).await.unwrap(); |
| assert_eq!(v, [0, 1, 2, 3]); |
| v.clear(); |
| reader.read_until(1, &mut v).await.unwrap(); |
| assert_eq!(v, [1]); |
| v.clear(); |
| reader.read_until(8, &mut v).await.unwrap(); |
| assert_eq!(v, [0]); |
| v.clear(); |
| reader.read_until(9, &mut v).await.unwrap(); |
| assert_eq!(v, []); |
| } |
| |
| // https://github.com/rust-lang/futures-rs/pull/1573#discussion_r281162309 |
| #[tokio::test] |
| async fn maybe_pending_seek() { |
| struct MaybePendingSeek<'a> { |
| inner: Cursor<&'a [u8]>, |
| ready: bool, |
| seek_res: Option<io::Result<()>>, |
| } |
| |
| impl<'a> MaybePendingSeek<'a> { |
| fn new(inner: &'a [u8]) -> Self { |
| Self { |
| inner: Cursor::new(inner), |
| ready: true, |
| seek_res: None, |
| } |
| } |
| } |
| |
| impl AsyncRead for MaybePendingSeek<'_> { |
| fn poll_read( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| buf: &mut ReadBuf<'_>, |
| ) -> Poll<io::Result<()>> { |
| Pin::new(&mut self.inner).poll_read(cx, buf) |
| } |
| } |
| |
| impl AsyncBufRead for MaybePendingSeek<'_> { |
| fn poll_fill_buf( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| ) -> Poll<io::Result<&[u8]>> { |
| let this: *mut Self = &mut *self as *mut _; |
| Pin::new(&mut unsafe { &mut *this }.inner).poll_fill_buf(cx) |
| } |
| |
| fn consume(mut self: Pin<&mut Self>, amt: usize) { |
| Pin::new(&mut self.inner).consume(amt) |
| } |
| } |
| |
| impl AsyncSeek for MaybePendingSeek<'_> { |
| fn start_seek(mut self: Pin<&mut Self>, pos: SeekFrom) -> io::Result<()> { |
| self.seek_res = Some(Pin::new(&mut self.inner).start_seek(pos)); |
| Ok(()) |
| } |
| fn poll_complete(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<u64>> { |
| if self.ready { |
| self.ready = false; |
| self.seek_res.take().unwrap_or(Ok(()))?; |
| Pin::new(&mut self.inner).poll_complete(cx) |
| } else { |
| self.ready = true; |
| cx.waker().wake_by_ref(); |
| Poll::Pending |
| } |
| } |
| } |
| |
| let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; |
| let mut reader = BufReader::with_capacity(2, MaybePendingSeek::new(inner)); |
| |
| assert_eq!(reader.seek(SeekFrom::Current(3)).await.unwrap(), 3); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[0, 1][..]); |
| assert!(reader.seek(SeekFrom::Current(i64::MIN)).await.is_err()); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[0, 1][..]); |
| assert_eq!(reader.seek(SeekFrom::Current(1)).await.unwrap(), 4); |
| assert_eq!(run_fill_buf!(reader).unwrap(), &[1, 2][..]); |
| Pin::new(&mut reader).consume(1); |
| assert_eq!(reader.seek(SeekFrom::Current(-2)).await.unwrap(), 3); |
| } |
| |
| // This tests the AsyncBufReadExt::fill_buf wrapper. |
| #[tokio::test] |
| async fn test_fill_buf_wrapper() { |
| let (mut write, read) = tokio::io::duplex(16); |
| |
| let mut read = BufReader::new(read); |
| write.write_all(b"hello world").await.unwrap(); |
| |
| assert_eq!(read.fill_buf().await.unwrap(), b"hello world"); |
| read.consume(b"hello ".len()); |
| assert_eq!(read.fill_buf().await.unwrap(), b"world"); |
| assert_eq!(read.fill_buf().await.unwrap(), b"world"); |
| read.consume(b"world".len()); |
| |
| let mut fill = spawn(read.fill_buf()); |
| assert_pending!(fill.poll()); |
| |
| write.write_all(b"foo bar").await.unwrap(); |
| assert_eq!(assert_ready!(fill.poll()).unwrap(), b"foo bar"); |
| drop(fill); |
| |
| drop(write); |
| assert_eq!(read.fill_buf().await.unwrap(), b"foo bar"); |
| read.consume(b"foo bar".len()); |
| assert_eq!(read.fill_buf().await.unwrap(), b""); |
| } |