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use crate::{
buf::{IoBuf, IoBufMut},
BufResult,
};
mod chan;
pub use chan::*;
mod buf_or_slice;
use buf_or_slice::*;
mod non_uring;
pub use non_uring::*;
pub trait ReadOwned {
async fn read<B: IoBufMut>(&mut self, buf: B) -> BufResult<usize, B>;
}
pub trait WriteOwned {
/// Write a single buffer, taking ownership for the duration of the write.
/// Might perform a partial write, see [WriteOwned::write_all]
async fn write<B: IoBuf>(&mut self, buf: B) -> BufResult<usize, B>;
/// Write a single buffer, re-trying the write if the kernel does a partial write.
async fn write_all<B: IoBuf>(&mut self, mut buf: B) -> std::io::Result<()> {
let mut written = 0;
let len = buf.bytes_init();
while written < len {
let (res, slice) = self.write(buf.slice(written..len)).await;
buf = slice.into_inner();
let n = res?;
if n == 0 {
return Err(std::io::Error::new(
std::io::ErrorKind::WriteZero,
"write zero",
));
}
written += n;
}
Ok(())
}
/// Write a list of buffers, taking ownership for the duration of the write.
/// Might perform a partial write, see [WriteOwned::writev_all]
async fn writev<B: IoBuf>(&mut self, list: Vec<B>) -> BufResult<usize, Vec<B>> {
let mut out_list = Vec::with_capacity(list.len());
let mut list = list.into_iter();
let mut total = 0;
while let Some(buf) = list.next() {
let buf_len = buf.bytes_init();
let (res, buf) = self.write(buf).await;
out_list.push(buf);
match res {
Ok(0) => {
out_list.extend(list);
return (
Err(std::io::Error::new(
std::io::ErrorKind::WriteZero,
"write zero",
)),
out_list,
);
}
Ok(n) => {
total += n;
if n < buf_len {
// partial write, return the buffer list so the caller
// might choose to try the write again
out_list.extend(list);
return (Ok(total), out_list);
}
}
Err(e) => {
out_list.extend(list);
return (Err(e), out_list);
}
}
}
(Ok(total), out_list)
}
/// Write a list of buffers, re-trying the write if the kernel does a partial write.
async fn writev_all<B: IoBuf>(&mut self, list: impl Into<Vec<B>>) -> std::io::Result<()> {
// FIXME: converting into a `Vec` and _then_ into an iterator is silly,
// we can probably find a better function signature here.
let mut list: Vec<_> = list.into().into_iter().map(BufOrSlice::Buf).collect();
while !list.is_empty() {
let res;
(res, list) = self.writev(list).await;
let n = res?;
if n == 0 {
return Err(std::io::Error::new(
std::io::ErrorKind::WriteZero,
"write zero",
));
}
let mut n = n;
list = list
.into_iter()
.filter_map(|item| {
if n == 0 {
Some(item)
} else {
let item_len = item.len();
if n >= item_len {
n -= item_len;
None
} else {
let item = item.consume(n);
n = 0;
Some(item)
}
}
})
.collect();
assert_eq!(n, 0);
}
Ok(())
}
}
#[cfg(all(test, not(feature = "miri")))]
mod tests {
use std::{cell::RefCell, rc::Rc};
use crate::{buf::IoBuf, io::WriteOwned, BufResult};
#[test]
fn test_write_all() {
enum Mode {
WriteZero,
WritePartial,
}
struct Writer {
mode: Mode,
bytes: Rc<RefCell<Vec<u8>>>,
}
impl WriteOwned for Writer {
async fn write<B: IoBuf>(&mut self, buf: B) -> BufResult<usize, B> {
assert!(buf.bytes_init() > 0, "zero-length writes are forbidden");
match self.mode {
Mode::WriteZero => (Ok(0), buf),
Mode::WritePartial => {
let n = match buf.bytes_init() {
1 => 1,
_ => buf.bytes_init() / 2,
};
let slice = unsafe { std::slice::from_raw_parts(buf.stable_ptr(), n) };
self.bytes.borrow_mut().extend_from_slice(slice);
(Ok(n), buf)
}
}
}
}
crate::start(async move {
let mut writer = Writer {
mode: Mode::WriteZero,
bytes: Default::default(),
};
let buf_a = vec![1, 2, 3, 4, 5];
let res = writer.write_all(buf_a).await;
assert!(res.is_err());
let mut writer = Writer {
mode: Mode::WriteZero,
bytes: Default::default(),
};
let buf_a = vec![1, 2, 3, 4, 5];
let buf_b = vec![6, 7, 8, 9, 10];
let res = writer.writev_all(vec![buf_a, buf_b]).await;
assert!(res.is_err());
let mut writer = Writer {
mode: Mode::WritePartial,
bytes: Default::default(),
};
let buf_a = vec![1, 2, 3, 4, 5];
writer.write_all(buf_a).await.unwrap();
assert_eq!(&writer.bytes.borrow()[..], &[1, 2, 3, 4, 5]);
let mut writer = Writer {
mode: Mode::WritePartial,
bytes: Default::default(),
};
let buf_a = vec![1, 2, 3, 4, 5];
let buf_b = vec![6, 7, 8, 9, 10];
writer.writev_all(vec![buf_a, buf_b]).await.unwrap();
assert_eq!(&writer.bytes.borrow()[..], &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
});
}
}
pub trait IntoHalves {
type Read: ReadOwned;
type Write: WriteOwned;
/// Split this into an owned read half and an owned write half.
fn into_halves(self) -> (Self::Read, Self::Write);
}