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|
use std::{
io::Result,
pin::Pin,
task::{Context, Poll},
};
struct ReaderThatPanicsAfterEof {
read_count: usize,
has_sent_eof: bool,
max_read: usize,
}
impl async_std::io::Read for ReaderThatPanicsAfterEof {
fn poll_read(
mut self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &mut [u8],
) -> Poll<Result<usize>> {
if self.has_sent_eof {
panic!("this should be unreachable because we should not poll after eof (Ready(Ok(0)))")
} else if self.read_count >= self.max_read {
self.has_sent_eof = true;
Poll::Ready(Ok(0))
} else {
self.read_count += 1;
Poll::Ready(Ok(buf.len()))
}
}
}
struct WriterThatTakesAWhileToFlush {
max_flush: usize,
flush_count: usize,
}
impl async_std::io::Write for WriterThatTakesAWhileToFlush {
fn poll_write(self: Pin<&mut Self>, _cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize>> {
Poll::Ready(Ok(buf.len()))
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
self.flush_count += 1;
if self.flush_count >= self.max_flush {
Poll::Ready(Ok(()))
} else {
cx.waker().wake_by_ref();
Poll::Pending
}
}
fn poll_close(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<()>> {
Poll::Ready(Ok(()))
}
}
#[test]
fn io_copy_does_not_poll_after_eof() {
async_std::task::block_on(async {
let mut reader = ReaderThatPanicsAfterEof {
has_sent_eof: false,
max_read: 10,
read_count: 0,
};
let mut writer = WriterThatTakesAWhileToFlush {
flush_count: 0,
max_flush: 10,
};
assert!(async_std::io::copy(&mut reader, &mut writer).await.is_ok());
})
}
|
